sailboat twin rudders

Search form

Docking a dual rudder sailboat.

Dual rudders, also referred to as twin or double rudders, are becoming more and more common in modern sailboats, both cruising and performance yachts alike. Since dual rudder boats handle differently than single rudders when maneuvering under engine power, it’s important for our charterers to know which boats in our fleet have dual rudders and to understand differences in the way they handle in tight spaces like dock slips and narrow fairways.

First, let’s have a look at the advantageous reasons dual rudders are becoming popular in modern boat design, as well as the challenges they can present to the uninformed. We’ll then give you some tips to help you get prepared for successful maneuvering in and out of the marina.

Dual Rudder Advantages

• To make for roomier cockpits and more space below deck for accommodations and storage, design trends are leaning toward wider transoms. Dual rudders improve the handling of a boat with a wide transom.
• Dual wheels accompany dual rudders, which means a more open cockpit layout and better visibility for the driver on the helm.
• Dual rudders facilitate better tracking. When the boat is heeling, there is always one rudder in the water, which means better control and a reduced tendency to round up.
• The propeller lies forward and between the twin rudders rather than in line with a single rudder. This means there will be no prop walk effect when backing up in reverse.

Dual Rudder Challenges

• Bow thrusters can help compensate in difficult conditions, but before you attempt to use bow thrusters, focus on learning how to dock without them first, and be sure to read this article: Bow Thruster Basics 

Twin Rudder Dual Rudder versus Single Rudder Modern Sailing.png

Boats with Dual Rudders in the Modern Sailing Fleet

Helix  (Beneteau Oceanis 30.1), Traharta  (Beneteau Oceanis 35)  Survivor  (Beneteau Oceanis 38),  Liberty  (Beneteau Oceanis 38.1),  Ry Whitt , (Jeanneau Sun Odyssey 409) and Attitude Adjustment (Beneteau Oceanis 41) are equipped with twin rudders and helms. Survivor and Liberty also have bow thrusters.

Tips for Docking a Dual Rudder Boat

Departing the Dock Slip

IMPORTANT: With a single rudder, when you apply a quick burst of throttle, prop wash over the rudder allows you to steer the boat without needing to accelerate. With dual rudders, you’ll need a longer burst to accelerate the boat enough to steer.

• If you need to turn your stern to starboard to head left out the fairway, then turn the wheel to starboard. This applies to B Dock boats Helix , Traharta , Survivor , and Liberty . 
• If you need to turn your stern to port to head right out a fairway, turn the wheel to port. On A Dock boats Ry Whitt and Attitude Adjustment , back up straight, and once sufficiently clear from the dock, turn away from shore to avoid nearby shallow areas. (Rocks - ouch!)
• You’ll need to use your best judgement to determine how far to turn the wheel – it will depend on the wind and current.

Let's imagine you're backing Traharta out of her slip on B Dock. Put the engine in reverse gear and apply a bit more throttle than you normally would on a single rudder boat. Keep the boat as straight in the slip as possible as you begin to back up. When the boat is 3/4 of the way out of the slip, turn the wheel to starboard, shift the engine into neutral gear and allow the boat to glide backwards into your starboard turn. When clear of the dock, turn the wheel to port, put the engine in forward gear, and slowly increase throttle as you head out of the fairway. 

While you're out on the water, we highly recommend you take some time to practice maneuvering a dual rudder sailboat in a safe area like an unoccupied mooring field. (Of course, always check the charts before entering an unfamiliar area to ensure adequate depth.) You can use mooring balls or buoys as points of reference as you get a feel for how the boat maneuvers. Be sure to give plenty of room for error around fixed objects. You’ll especially want to practice slowing the boat to get a feel for the speed at which it loses steerage. This will help you to better judge the minimum amount of speed you'll need to maintain control of the boat as you maneuver.

Entering the Dock Slip

Heading down the fairway and approaching the dock, once again, you’ll need a bit more momentum than you would in a single rudder boat. As you begin to turn toward the dock slip, don’t slow down too much or you could lose steerage and miss. Maintain momentum until you have completed the turn and the boat is aligned with the slip. When you enter the slip, at the last moment, reverse the engine and throttle up to stop the boat. Because you entered the slip with more momentum than you would on a single rudder boat, you’ll also need to apply more RPMs to stop the boat. Again, use your best judgement on how high to throttle up based on the conditions.

Want More Training?

Here's some of the ways you can get docking practice and training with one of our experienced instructors:

• ASA 118, Docking Endorsement Clinic
• Platinum Fleet Dockkng & Maneuvering Clinic
• Development Sails
• Private Lessons

Need Help at the Dock?

Whenever you find yourself approaching a docking situation that feels uncomfortable for you (such as in a strong wind), it's always okay to ask for help. Call the Modern Sailing team on VHF radio channel 71 if you would like some help with a slip-line departure or dock entry. Please be aware that only our licensed and certified instructors are qualified to provide docking instruction, but a fleet team member standing on the dock can help you cast off or catch your lines as you depart or come in. We're happy to help!

Did you find this article helpful? See our Member Resources library for more like it.

Share This Page

Testimonials.

The meeting room was quite adequate and the location most convenient, but the course outline and instruction were outstanding. Modern Sailing is fortunate to have such a well organized instructor in Mr. Stan Lander who teaches very well from a rich professional background. Mr. Lander was generous with his time and patiently in helping students who needed more attention or time in understanding various aspects of the curriculum.

All of the courses and my instructors (JT and Stan) were extremely professional and full of knowledge and experience. I found I was able to learn from their experiences beyond the scope of the courses, and look forward to future opportunities to do so. I would highly recommend Modern Sailing to anyone.

Here are some snaps of Our Saturday, August 20, 2022 Modern Sailing Expedition with Captain Robert Bivin, who was outstanding. Please convey photos and thanks to him. He is an outstanding individual, leader and sailing instructor. His knowledge and experience made us all feel safe and our Farallones Day Trip educational and just amazing. 

View All Testimonials

Follow us on Social Media

Modern Sailing School & Club

Sausalito Location 2310 Marinship Way, Sausalito, CA 94965 (415) 331-8250 (800) 995-1668

Berkeley Location 1 Spinnaker Way, Berkeley, CA 94710 (415) 331-8250 (800) 995-1668

Map / Directions

You are here.

• Featured Listings
• Beneteau Sailboats
• Excess Catamarans
• Powerboat Listings
• Sailboat Listings
• Catamaran Listings
• Recent Price Drop
• See All Team Members
• Why Hire Team Murray Yacht Sales
• Your Saved Searches
• Ask a Question

Twin Rudders on a Sailboat: Increased control and safety

• Pingback: Shallow Water Sailing and Cruising (Twin Rudder / Centerboard Option)
• Pingback: Beneteau Sense 50 #36 Commissioning Notes

Comments are closed.

My Cruiser Life Magazine

All About the Rudder on a Sailboat

The rudder on a sailboat is one of those important parts that often gets overlooked. It’s hidden underwater most of the time and usually performs as expected when we ask something of it.

But when was the last time you seriously considered your sailboat rudder? Do you have a plan if it fails? Here’s a look at various designs of sail rudder, along with the basics of how it works and why it’s there.

Table of Contents

How are sailboat rudders different than keels, how does the rudder work, wheel steering vs. tiller steering, full keel rudder sailboat, skeg-hung rudders, spade rudder, variations on designs, emergency outboard rudder options, looking to sail into the sunset grab the wheel, steer your sail boat rudder, and get out there, sail boat rudder faqs.

What Is a Boat Rudder?

The rudder is the underwater part of the boat that helps it turn and change direction. It’s mounted on the rear of the boat. When the wheel or tiller in the cockpit is turned, the rudder moves to one side or another. That, in turn, moves the boat’s bow left or right.

When it comes to sailing, rudders also offer a counterbalance to the underwater resistance caused by the keel. This enables the boat to sail in a straight line instead of just spinning around the keel.

Sailboat hull designs vary widely when you view them out of the water. But while the actual shape and sizes change, they all have two underwater features that enable them to sail–a rudder and a keel.

The rudder is mounted at the back of the boat and controls the boat’s heading or direction as indicated by the compass .

The keel is mounted around the center of the boat. Its job is to provide a counterbalance to the sails. In other words, as the wind presses on the sails, the weight of the ballast in the keel and the water pressure on the sides of the keel keeps the boat upright and stable.

When sailing, the keel makes a dynamic force as water moves over it. This force counters the leeway made by air pressure on the sails and enables the boat to sail windward instead of only blowing downwind like a leaf on the surface.

The rudder is a fundamental feature of all boats. Early sailing vessels used a simple steering oar to get the job done. Over the years, this morphed into the rudder we know today.

However, thinking about a rudder in terms of a steering oar is still useful in understanding its operation. All it is is an underwater panel that the helmsperson can control. You can maintain a course by trailing the oar behind the boat while sailing. You can also change the boat’s heading by moving it to one side or the other.

The rudders on modern sailboats are a little slicker than simple oars, of course. They are permanently mounted and designed for maximum effectiveness and efficiency.

But their operating principle is much the same. Rudders work by controlling the way water that flows over them. When they move to one side, the water’s flow rate increases on the side opposite the turn. This faster water makes less pressure and results in a lifting force. That pulls the stern in the direction opposite the turn, moving the bow into the turn.

Nearly all boats have a rudder that works exactly the same. From 1,000-foot-long oil tankers to tiny 8-foot sailing dinghies, a rudder is a rudder. The only boats that don’t need one are powered by oars or have an engine whose thrust serves the same purpose, as is the case with an outboard motor.

Operating the Rudder on a Sailboat

Rudders are operated in one of two ways–with a wheel or a tiller. The position where the rudder is operated is called the helm of a boat .

Ever wonder, “ What is the steering wheel called on a boat ?” Boat wheels come in all shapes and sizes, but they work a lot like the wheel in an automobile. Turn it one way, and the boat turns that way by turning the rudder.

A mechanically simpler method is the tiller. You’ll find tiller steering on small sailboats and dinghies. Some small outboard powerboats also have tiller steering. Instead of a wheel, the tiller is a long pole extending forward from the rudder shaft’s top. The helmsperson moves the tiller to the port or starboard, and the bow moves in the opposite direction. It sounds much more complicated on paper than it is in reality.

Even large sailboats will often be equipped with an emergency tiller. It can be attached quickly to the rudder shaft if any of the fancy linkages that make the wheel work should fail.

Various Sail Boat Rudder Designs

Now, let’s look at the various types of rudders you might see if you took a virtual walk around a boatyard. Since rudders are mostly underwater on the boat’s hull, it’s impossible to compare designs when boats are in the water.

Keep in mind that these rudders work the same way and achieve the same results. Designs may have their pluses and minuses, but from the point of view of the helmsperson, the differences are negligible. The overall controllability and stability of the boat are designed from many factors, and the type of rudder it has is only one of those.

You’ll notice that rudder design is closely tied to keel design. These two underwater features work together to give the boat the sailing characteristics the designer intended.

The classic, robust offshore sailboat is designed with a full keel that runs from stem to stern. With this sort of underwater profile, it only makes sense that the rudder would be attached to the trailing edge of that enormous keel. On inboard-powered sailboats, the propeller is usually mounted inside an opening called the aperture between the keel and rudder.

The advantages of this design are simplicity and robustness. The keel is integrated into the hull and protects the rudder’s entire length. Beyond reversing into an obstacle, anything the boat might strike would hit the keel first and would be highly unlikely to damage the rudder. Not only does the keel protect it, but it also provides a very strong connection point for it to be attached to.

Full keel boats are known for being slow, although there are modern derivatives of these designs that have no slow pokes. Their rudders are often large and effective. They may not be the most efficient design, but they are safe and full keels ride more comfortably offshore than fin-keeled boats.

Plenty of stout offshore designs sport full keel rudders. The Westsail 38s, Lord Nelsons, Cape Georges, Bristol/Falmouth Cutters, or Tayana 37s feature a full keel design.

A modified full keel, like one with a cutaway forefoot, also has a full keel-style rudder. These are more common on newer designs, like the Albergs, Bristols, Cape Dorys, Cabo Ricos, Island Packets, or the older Hallberg-Rassys.

A design progression was made from full keel boats to long-fin keelboats, and the rudder design changed with it. Designers used a skeg as the rudder became more isolated from the keel. The skeg is a fixed structure from which you can mount the rudder. This enables the rudder to look and function like a full keel rudder but is separated from the keel for better performance.

The skeg-hung rudder has a few of the same benefits as a full keel rudder. It is protected well and designed robustly. But, the cutaways in the keel provide a reduced wetted surface area and less drag underwater, resulting in improved sailing performance overall.

Larger boats featuring skeg-mounted rudders include the Valiant 40, Pacific Seacraft 34, 37, and 40, newer Hallberg-Rassys, Amels, or the Passport 40.

It’s worth noting that not all skegs protect the entire rudder. A partial skeg extends approximately half the rudder’s length, allowing designers to make a balanced rudder.

With higher-performance designs, keels have become smaller and thinner. Fin keel boats use more hydrodynamic forces instead of underwater area to counter the sail’s pressure. With the increased performance, skegs have gone the way of the dinosaurs. Nowadays, rudders are sleek, high aspect ratio spade designs that make very little drag. They can be combined with a number of different keel types, including fin, wing keels , swing keels, or bulb keels.

The common argument made against spade rudders is that they are connected to the boat by only the rudder shaft. As a result, an underwater collision can easily bend the shaft or render the rudder unusable. In addition, these rudders put a high load on the steering components, like the bearings, which are also more prone to failure than skeg or full keel designs. For these reasons, long-distance cruisers have traditionally chosen more robust designs for the best bluewater cruising sailboats .

But, on the other hand, spade rudders are very efficient. They turn the boat quickly and easily while contributing little to drag underwater.

Spade rudders are common now on any boat known for performance. All racing boats have a spade rudder, like most production boats used for club racing. Pick any modern fin keel boat from Beneteau, Jeanneau, Catalina, or Hunter, and you will find a spade rudder. Spade rudders are common on all modern cruising catamarans, from the Geminis to the Lagoons, Leopards, and Fountaine Pajots favored by cruisers and charter companies.

Here are two alternative designs you might see out on the water.

Transom-Hung or Outboard Rudders

An outboard rudder is hung off the boat’s transom and visible while the boat is in the water. Most often, this design is controlled by a tiller. They are common on small sailing dingies, where the rudder and tiller are removable for storage and transport. The rudder is mounted with a set of hardware called the pintle and gudgeon.

Most outboard rudders are found on small daysailers and dinghies. There are a few classic big-boat designs that feature a transom-hung rudder, however. For example, the Westsail 38, Alajuela, Bristol/Falmouth Cutters, Cape George 36, and some smaller Pacific Seacrafts (Dana, Flicka) have outboard rudders.

Twin Sailing Rudder Designs

A modern twist that is becoming more common on spade rudder boats is the twin sailboat rudder. Twin rudders feature two separate spade rudders mounted in a vee-shaped arrangement. So instead of having one rudder pointed down, each rudder is mounted at an angle.

Like many things that trickle down to cruising boats, the twin rudder came from high-performance racing boats. By mounting the rudders at an angle, they are more directly aligned in the water’s flow when the boat is healed over for sailing. Plus, two rudders provide some redundancy should one have a problem. The twin rudder design is favored by designers looking to make wide transom boats.

There are other, less obvious benefits of twin rudders as well. These designs are easier to control when maneuvering in reverse. They are also used on boats that can be “dried out” or left standing on their keel at low tide. These boats typically combine the twin rudders with a swing keel, like Southerly or Sirius Yachts do. Finally, twin rudders provide much better control on fast-sailing hulls when surfing downwind.

Unbalanced vs. Balanced Rudders

Rudders can be designed to be unbalanced or balanced. The difference is all in how they feel at the helm. The rudder on a bigger boat can experience a tremendous amount of force. That makes turning the wheel or tiller a big job and puts a lot of strain on the helmsperson and all of the steering components.

A balanced rudder is designed to minimize these effects and make turning easier. To accomplish this, the rudder post is mounted slightly aft of the rudder’s forward edge. As a result, when it turns, a portion of the leading edge of the rudder protrudes on the opposite side of the centerline. Water pressure on that side then helps move the rudder.

Balanced rudders are most common in spade or semi-skeg rudders.

Sail Rudder Failures

Obviously, the rudder is a pretty important part of a sailboat. Without it, the boat cannot counter the forces put into the sails and cannot steer in a straight line. It also cannot control its direction, even under power.

A rudder failure of any kind is a serious emergency at sea. Should the rudder be lost–post and all–there’s a real possibility of sinking. But assuming the leak can be stopped, coming up with a makeshift rudder is the only way you’ll be able to continue to a safe port.

Rudder preventative maintenance is some of the most important maintenance an owner can do. This includes basic things that can be done regularly, like checking for frayed wires or loose bolts in the steering linkage system. It also requires occasionally hauling the boat out of the water to inspect the rudder bearings and fiberglass structure.

Many serious offshore cruisers install systems that can work as an emergency rudder in extreme circumstances. For example, the Hydrovane wind vane system can be used as an emergency rudder. Many other wind vane systems have similar abilities. This is one reason why these systems are so popular with long-distance cruisers.

There are also many ways to jury rig a rudder. Sea stories abound with makeshift rudders from cabinet doors or chopped-up sails. Sail Magazine featured a few great ideas for rigging emergency rudders .

Understanding your sail rudder and its limitations is important in planning for serious cruising. Every experienced sailor will tell you the trick to having a good passage is anticipating problems you might have before you have them. That way, you can be prepared, take preventative measures, and hopefully never deal with those issues on the water.

What is the rudder on a sailboat?

The rudder is an underwater component that both helps the sailboat steer in a straight line when sailing and turn left or right when needed.

What is the difference between a rudder and a keel?

The rudder and the keel are parts of a sailboat mounted underwater on the hull. The rudder is used to turn the boat left or right, while the keel is fixed in place and counters the effects of the wind on the sails.

What is a rudder used for on a boat?

The rudder is the part of the boat that turns it left or right

Matt has been boating around Florida for over 25 years in everything from small powerboats to large cruising catamarans. He currently lives aboard a 38-foot Cabo Rico sailboat with his wife Lucy and adventure dog Chelsea. Together, they cruise between winters in The Bahamas and summers in the Chesapeake Bay.

Leave a comment

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

While mini keels and daggerboards provide lateral resistance to leeway, rudders allow directional control and steerage. Catamarans always have twin rudders which contribute to their safety. Having reliable steerage on any cruising boat is essential and cannot be overestimated. Twin rudders provide positive redundancy, superior tracking, and reduce the loads on autopilots. Just as the majority of today's cruising catamarans are mini keelers, 90% of them are also equipped with fixed spade rudders. However, there are a number of variations that are perfectly suited for the various adaptations of a cruising multihull .

Usually multihull rudders are much smaller than their monohull counterparts. There are four reasons for that: First, there are two rudders, unlike the single one on a monohull, so the lateral area is combined. Second, a multihull will typically travel faster than a ballasted boat, therefore rudders do not have to be as large. The slower the boat the larger the rudder has to be in order to steer effectively. Have you ever seen the rudder of a tug boat? They are 3 times the size of your average door. Thirdly, rudders will always remain nearly vertical and so be more effective. Lastly, the narrow high-aspect-ratio hulls of a catamaran will help the boat track straight and not require a large rudder surface area as there is less directional correction necessary. Designing a multihull's rudder is a challenge however. The performance window of a catamaran is much higher and a rudder that has to work at 3 knots must be prevented from cavitating at 25 knots when it surfs. Cavitation, or ventilation, as it is sometimes referred to, happens when, at very high speed, air is drawn down the low pressure side and detaches the flow of water around the rudder area.

There are also additional problems for multihull designers because the configuration of a catamaran, with its shallow hull, makes rudders much more vulnerable to impacts than on monohulls, which have a 7' keel protecting them. Normally the depth of the rudders are slightly less than the mini keels or skegs ahead of them, and their position should be roughly 20% aft of the lateral pivot point

of the vessel. Generally, non-hydraulically operated rudders on multihulls are connected to one another by either a crossbar tube or another type of mechanical linkage. This provides a straightforward and reliable system. If one side fails, one should have the ability to quickly isolate one rudder in order to regain proper steerage. By far the most popular type are the spade rudders that are mounted on either stainless steel or aluminum (sometimes even aramid) stern-tube rudder stocks. In case of a failure emergency tillers can be quickly fitted to the top of the stocks. Fixed spade rudders are also referred to as "balanced," as the rudder stock enters the foil aft of the leading edge, leaving an area forward, which aids in turning the rudder. Spade rudders are usually located well aft for good lever action; they are also the most efficient type. Often the gap between the hull and the rudders' upper edge is less than one inch, making the hull act like an endplate. Spade-type rudders are straightforward to build and provide the most sensitive feedback to the helmsman. As many of today's multihulls are fitted with hydraulic steering systems, which are known for the absence of steering "feedback" to the helmsman, the spade-hung rudder nevertheless will be the best means to translate the forces back to the wheel. Freely suspended rudders are not without vices; they can snag lines and are vulnerable to damage, especially if they are not protected by skegs or mini-keels. Another type is the skeg-hung rudder, which has the advantage of being mounted behind a solid appendage. It is not as easy to build and has less feedback than the balanced, free hung rudder. Both types should be designed to take the weight of the boat without damage when beaching.

Unlike the above fixed types, lifting rudders allow a reduction of draft. They can either be the daggerboard - vertically lifting type, hung on transoms - or built into hinging stern sections. Another variety is the centerboard kick-up type, usually hinged onto transoms. Presently only few production manufacturers equip their catamarans with lifting rudders. They are more expensive to construct, are complex in nature and lack the efficiency of the fixed rudder. Anything moving more than it must presents a potential weak spot, and the forces of Nature will usually find them at the most inopportune time. Having simple, reliable rudders is of the essence on a well-designed multihull.

below Beautifully finished in Aston Martin-blue, like the owner's car, this top-of-the-line catamaran is ready for launch. Note the anodes on both sides of the aluminum semi-balanced rudder.

"The machine does not isolate man from the great problems of nature, but plunges him more deeply into them."

~ Antoine de Saint-Exupéry - Wind, Sand and Stars

008 by Gregor Tarjan. Click here for terms of use. ■ ®

Halyard and reefing winches are firmly riveted to aluminum base plates and conveniently located at the foot of the mast, ready to hoist and douse sails.

Continue reading here: Configuration Types

Was this article helpful?

Recommended Programs

Myboatplans 518 Boat Plans

Related Posts

• Appendages - Catamarans Guide
• Catamaran Design Guide - Catamarans Guide
• Using the rudder - Sailing Techniques
• Keel and Rudder Design Ftv

Readers' Questions

How to calculate rudder area for a performance cruising catamaran?

Calculating the rudder area for a performance cruising catamaran involves considering factors such as the boat's length, displacement, and desired maneuverability. Here is a general approach to calculating rudder area: Determine the displacement of the catamaran: Displacement refers to the weight of the boat when it is fully loaded. Measure or obtain the displacement of the catamaran in pounds or kilograms. Calculate the wetted surface area: Wetted surface area refers to the surface area of the hulls that are in contact with water. Use the catamaran's length, beam, and draft to estimate the wetted surface area. This can be done using empirical formulas specific to catamarans or by using more precise methods, such as integrating the hull shape's cross-sections. Determine the Lateral Plane Area Coefficient (LPAC): LPAC is a coefficient used to determine the rudder area based on the wetted surface area. It depends on the desired maneuverability and varies for different types of vessels. For performance cruising catamarans, a typical LPAC value ranges from 0.03 to 0.05. Calculate the rudder area: Multiply the wetted surface area by the LPAC to obtain the rudder area. The formula is as follows: Rudder Area = Wetted Surface Area x LPAC For example, if the wetted surface area of a catamaran is 500 square feet, and the LPAC is 0.04: Rudder Area = 500 x 0.04 = 20 square feet. Remember that this is a general approach, and it is always recommended to consult with naval architects or boat designers who have expertise in catamarans for more precise calculations specific to your vessel.

Do rudders mounted underneath the bridgedeck of a wharram catamaran work?

Yes, they do work. Rudders mounted underneath a catamaran's bridgedeck can provide the same directional control as rudders mounted at the stern of a single-hulled vessel. This is especially true for sailing catamarans, which are designed with a long bridgedeck that extends forward of the transoms to create a wide platform for steering and control. Because this bridgedeck extends far enough out of the water, it can accommodate a rudder and provide the same steering capabilities as a traditional rudder.

How to tune catamaran rudders?

First, check your boat's steering system and adjust the rudder angle as needed. Check the tension on the steering cables and make sure they are properly adjusted. Make sure the rudders are properly aligned with the waterline. Trim the sails to the optimal angle for the prevailing conditions. Place the rudders at the correct angle to the waterline. Test the steering at slow and fast speeds. If necessary, make adjustments to the rudder angle to ensure maximum response. Test the steering at different angles of heel to determine if the helm is balanced. Make sure the rudders are kept in good condition and regularly maintained.

How to build mini keels for a catamaran?

Building mini keels for a catamaran requires precise measurements, proper materials, and some woodworking skills. Here's a step-by-step guide on how to build mini keels for a catamaran: Gather the materials: You will need marine-grade plywood, epoxy resin, fiberglass cloth, sandpaper, and marine paint. Measure and design: Decide the size and shape of the mini keels based on your catamaran's specifications. Measure the keel's length, width, and thickness. Sketch the design on paper. Cut the plywood: Using a jigsaw or a hand saw, cut the marine-grade plywood according to the dimensions outlined in your design. Make sure to cut two identical shapes for each keel. Shape the keel: Using sandpaper, smooth the edges and shape the plywood according to your design. Take your time to achieve the desired keel shape. Apply epoxy resin: Coat both sides of each keel with epoxy resin to seal the plywood. Follow the epoxy resin manufacturer's instructions for mixing and applying the resin. Allow it to cure completely. Apply fiberglass cloth: Cut fiberglass cloth slightly larger than the keel's dimensions. Apply epoxy resin to the keel's surface and lay the fiberglass cloth over it. Smooth out any air bubbles or wrinkles using a squeegee or putty knife. Apply more epoxy resin on top of the fiberglass to fully saturate it. Allow it to cure. Sand and paint: Once cured, sand the keel to remove any rough spots or imperfections. Make sure the surface is smooth and ready for painting. Apply marine paint to the keel, using several coats to ensure durability. Install the keels: Consult your catamaran's design or consult with a boat builder to determine the optimal placement for the mini keels. Install the keels onto the catamaran's hulls using marine-grade screws or bolts. Make sure they are securely fastened. Final touch-ups: Give a final sanding to the keels after they are installed to ensure a smooth finish. Apply additional coats of marine paint if necessary. Remember to take safety precautions, such as wearing gloves and protective eyewear, when working with epoxy resin and power tools. Additionally, consulting a boat builder or experienced sailor for advice and guidance is recommended to ensure the mini keels are correctly designed and installed for optimal performance and stability.

How weel do twin rudders track?

Twin rudders usually track very well, as the two rudders create an increased force and rudder area compared to a single rudder. This allows for more precise control and little to no lateral drift.

Do catamarans have keels?

No, catamarans do not have keels.

Can rudder propeller be used for catamaran boats?

Yes, rudder propellers can be used for catamaran boats. They are commonly used as a propulsion system to provide thrust and maneuverability. Rudder propellers are typically designed with two propeller blades mounted on a common shaft. The two blades can be adjusted independently, allowing the boat to move forward and backward, as well as turn.

How to makea catamaran rudder?

To make a catamaran rudder, you will need the following materials and tools: Materials: - Marine-grade plywood or fiberglass sheet - Stainless steel or aluminum for the rudder stock - Nuts, bolts, and washers - Epoxy resin and hardener - Fiberglass cloth - Sandpaper - Marine-grade paint or varnish Tools: - Jigsaw or handsaw - Drill - Router or file - Screwdriver - Paintbrush - Sanding block or power sander Here are the general steps to make a catamaran rudder: Design the rudder: Determine the size and shape of the rudder. Make sure it is suitable for the specific catamaran design and sailing conditions. Create a template: Trace the outline of the rudder on a piece of cardboard or plywood to create a template. Cut it out and refine the shape until you are satisfied with the design. Transfer the template to the rudder material: Place the template on the marine-grade plywood or fiberglass sheet. Use a pencil or marker to trace the outline onto the material. Cut out the rudder shape: Use a jigsaw or handsaw to carefully cut along the traced outline. Take your time and ensure smooth, even cuts. Sanding and shaping: Use sandpaper or a power sander to smooth the edges and shape the rudder. Round the leading and trailing edges for better hydrodynamics. Take your time and regularly check the symmetry and balance of the rudder. Prepare the rudder stock: Cut and shape the stainless steel or aluminum for the rudder stock. Drill holes in the stock for attaching to the rudder and boat. Attach the rudder stock: Use epoxy resin to bond the rudder stock to the rudder. Reinforce with fiberglass cloth and more epoxy for added strength. Finishing touches: Sand the entire rudder surface to create a smooth finish. Apply multiple coats of marine-grade paint or varnish for protection against water and UV rays. Allow each coat to dry completely before applying the next. Install the rudder: Attach the rudder to the catamaran using appropriate nuts, bolts, and washers. Ensure it is securely fastened and aligned properly for optimal performance. Remember to consult any specific plans or guidelines provided by your boat's manufacturer or a professional boat builder.

Do catamarans have rudders?

Yes, catamarans typically have two rudders located at the back of the hulls.

Do catamarans need rudder?

Yes, catamarans need rudders for navigational control. The rudder is connected to a steering system which helps to control the direction of the vessel.

Do a catamaran need one or two rudders?

A catamaran typically has two rudders.

Attainable Adventure Cruising

The Offshore Voyaging Reference Site

• Q&A, Coming Alongside (Docking) With Twin Rudders

I have a boat with twin rudders and a single propeller on centre line. Will your docking techniques in this Online Book work for me and, if not, what should I do?

Login to continue reading (scroll down)

Please Share a Link:

More Articles From Online Book: Coming Alongside (Docking) Made Easy:

• Introduction to Coming Alongside (Docking) Online Book
• 10 Tips to Make Coming Alongside (Docking) Easy
• Coming Alongside (Docking) in 4 Easy Steps
• Rigging The Spring That Makes Docking Easy, Or an Alternative
• 10 Ways to Make Your Boat Easier to Bring Alongside a Dock
• Coming Alongside (Docking)—Manoeuvring in Close Quarters
• Coming Alongside (Docking)—The Final Approach
• Coming Alongside (Docking)—Taming the Wind
• Coming Alongside (Docking)—Backing In, Part 1
• Coming Alongside (Docking)—Backing In, Part 2
• Q&A Backing Out of a Bow-In Med Moor
• 14 Tips for Coming Alongside Single-handed—Part 1
• 14 Tips To Come Alongside Single-Handed—Part 2
• Leaving a Dock Against an Onshore Wind—Part 1
• Leaving a Dock Against an Onshore Wind—Part 2
• Going Alongside (Docking) in Current—Fundamentals
• Going Alongside (Docking) in Current—Turning in Confined Spaces
• Going Alongside (Docking) in Current—Backing In
• Going Alongside (Docking)—12 More Tips and Tricks

Hi John I have an Ovni 445 with twin rudders. I agree with you for the usefulness of a bow thruster , but also of the Maxprop propeller. I can turn the boat in one side “in her lenght” with the propeller only , when the wind is light (big windage…) KR

That’s good news, indicating that twin rudders retain more prop walk than I feared. That said, I still think that a bow thruster is a good idea for these boats because of the lack of prop wash. (With prop wash I think you would be able to operate without a thruster even in higher winds, although that said, lifting keel boats can be challenging to dock.)

I’m hoping that you’ll cogitate, perhaps even ruminate, on coming along side with a heavy current, perhaps even one that’s in opposition to the wind. If you’re interested in more specificity – we back our 45 foot Norseman along about 275 feet of before getting to our section of dock. The marina is in the mouth of a river that when the tide is going out gives us a 3 knot current pushing off the dock. The fairway is about 65 feet wide.

Hi Dartanyon,

Wow, that’s challenging! I will give it some deep cogitation.

When we had our 55 foot Aluminium lift keel boat designed the designers informed us that due to our request to have a minimum draft of 1,5 meters we had to have twin rudders…For the reasons obvious I was mordicus against it given the crowed entrances to locks and harbours in the Netherlands. They than came up with the solution to fit a, much smaller, third rudder behind the propellor. Jefa had done this a few times before and they designed the rudder geometry. We now sailed 15000 Nm in four seasons and are very happy with this configuration although it’s more complicated and costly… And yes we also have a bow thruster but only have to use it in unfavourable windy conditions.

That’s interesting and good to hear it works. Like you, the complications would worry me, but then boats are all about tradeoffs and it sounds like you have balanced yours well.

Hi Douwe, is it the wonderful ship Stayer you are writing about?

Hi Svein, Yes it is… hopefully you and your wife are well and we can meet again in the near future!

Hi Douwe, we are fine sailing in Denmark in our small double- ender hoping to get home in the North before the sea ice close our harbour. I believe Stayer represent a new positive development in yacht construction with her tree rudders and many other solutions. I have observed Stayer enter rather difficult harbors in Loften and docking elegantly without using trusthers. However the rigg of Stayer is very tall. How is Stayer to handle when docking in much wind? When I saw her there was no wind. I have observed that Stayer is extremely fast when sailing off-shore. Is she also comfortable off-shore? To mee Stayer seems like a unique modern construction: Good in shallow coastal waters, but also a fine long distance sailor. We would like to meet you again and discuss you experiences with Stayer.

For those considering a bow thruster, check out a Yacht Thruster. It’s an external unit, easy to install and able to be run for long durations because the motor is underwater-no overheating issues. It’s not speed robbing like a tunnel and requires one hole the size of a typical thru-hull. I was skeptical at first about having this torpedo shaped device hanging from the hull. But after three years, no complaints. One benefit, if the next owner doesn’t want it, it can easily removed and hole faired in a jiffy.

That’s interesting, although I have to say that the thought of adding such a thing to a hull that was not initially designed for it, particularly structurally, worries me a lot.

Just to be clear for everyone else, I’m not advocating for bow thrusters and in fact don’t recommend them, except for very special situations like twin rudder boats.

your observing that dual rudders are becoming more commonplace makes me wonder why ad this defeats the k i s s principle so important with sail craft especially…is also just that much more to incur damage…i think more than the std single rudder is jst asking for trouble

Hi Richard,

I agree. We are not fans of twin rudders here at AAC.

My limited experience with twin rudder boats has highlighted a few things for me.

Like most boats, you can usually get the stern into the wind even if it is against the direction of prop walk. Once you are in this orientation, it is relatively stable even without prop walk to help. I use this trick a lot on full keel boats and it works reasonably well here as well.

Backing down fairways can be a better bet as it makes changing direction easier and these boats usually back just fine. By getting steerage up in reverse out in the open, you deal with the harder to control direction change (assuming it is not a tailwind) out there.

Twin rudders is really unforgiving for people who drive as if they are using an outboard. It is crucial that you steer for the direction of water flow across the rudder and not whatever the engine is doing (this seems to be an issue for a lot of people based on my informal observation).

I learned something new in our single screw single rudder boat that should have been obvious a few weeks ago. I was trying to turn around our 36′ boat in an ~50′ wide creek that was turning hard to the left with the current behind us. I started my usual back and fill turn to starboard for our prop walk and the boat didn’t seem to want to turn. I then realized that the current on the outside of the turn was going faster so I switched to a port turn and the boat went around really easy despite being against the prop walk.

Great tips, as always, thank you. I had not really thought about the importance of realizing that water flow over the rudder will be different from the way the prop is driving for some time after changing the latter. I will need to incorporate that in a couple of future posts, so thanks again.

Hi John As I do most of my sailing single handed, I am still crossing my fingers that you will make another video of you coming alongside singlehanded using the balanced-point aft running spring and tying everything off singlehanded. Please 🙂 Kind regards, Peter

That reminds me that I need to do a single handed chapter, will do. Not sure a video will help a lot since all you would see is me making lines fast instead of me. Not a lot of value. Rather I think we need to explore getting the first line ashore and the dangers of getting off a boat that’s in gear.

Anyway, cogitating now.

Looking very much forward to reading that chapter. Happy cogitating ?

Hi John, did you already come around to that “single handed chapter”? I’ve just searched AAC and couldn’t find one except preparing for a singlehanded atlantic crossing?

Not yet. I plan to get back to docking this summer, now that I have MC back in the water.

Hi all, on two delivery trips with french raceboats (Archambault 35) I found that these boats -twin rudders, very wide stern- really ask for being backed into their slots. As Eric mentions, they are backing very well pretty much regardless of wind direction. Position one crewmember at the docking side of the pushpit, get a line ashore and power forward to pull the boat alongside. Works really well because of the wide transom and the resulting good leverage. The challenge comes when singlehanded, you have to be quick as the distance from tiller to the boat’s corner is rather long on this type of boat.

That makes sense. Another data point for my backing in chapter, thanks.

Hi John and Douwe, On my brothers sail boat Flyer, where the prop is maybe 20ft forward from the rudder, I guess he would love to have a small 2nd rudder just behind the prop. When we recently hauled out my motorboat, was surprised to see the (large)rudders could only swing 60 degrees from side to side, while the rudder indicators show about 100 degrees and yet it handles very well in tight spaces. During my hi-school summer hollidays I worked on river Rhine barges, single prop and two rudders about 3 ft apart, but could turn the rudders close to 180 degrees. No bow thrusters in those days, but did have a bow (balanced) rudder that could be lowered and handled with a long tiller. As you know, now the maneuvring is (greatly?) enhanced with articulated rudders. Has that system found its way on pleasure boats? Rene

Your focus is on larger boats with inboards. As multihull sailor, even the larger cats I’ve sailed or owned have always been outboard powered. With twin screws that far apart you have a whole world of tricks that I’m not going to get into. Some have had single engines. And what all of these have in common is trivial prop walk and no flow over the rudder.

But many small boats with outboards have something else they forget about all the time. The thrust can be directed by turning the motor. Unlike power boats, they have a rudder that works without prop wash.

One handy trick, say coming alongside on port, is to turn the rudder to starboard (tiller to port) while turning the engine to port and bumping reverse. The result is that the boat goes mostly sideways, slowly coming to a stop just touching the dock. Quite handy on a bulkhead with boats fore and aft.

There are other variations.

So true. The most manoeuvrable boat I have ever handled was a 28′ power cat with twin outboards. Even with a disabled 35′ sailboat lashed alongside I was able to work her into a tight marina and drop the sailboat off with no issues at all.

I have concern that the balance point spring aft method may not work like it would with a single screw/single rudder vessel. In a normal setup the prop wash over the rudder and the rudder angle dictates where the bow and stern go when you are pivoting on that spring. A twin rudder will only be able to push ahead on that spring and not control any direction of bow/stern. In my opinion, I think a further aft spring would help with keeping the boat pinned to a dock as there wouldn’t be as easy of a pivot. Once pressed to the dock other lines could be made off the the thrust left off.

Am I making sense with this? Just to be clear, I’m still suggesting a quarter point for a spring, but only a little more aft for a single screw/twin rudder yacht.

Thanks for the very detailed posts on this too, by the way! Hope your cruising has gone well this season!

Yes, of course you are right, the balance point spring won’t work nearly as well with twin rudders. I should have thought of that, thanks for pointing it out.

As to moving the spring further back, that will help in some cases, but in others, such as a hard offshore wind, I think it could be a problem since it would be difficult to get the bow in, and there’s a good chance that as the spring is loaded the stern will come in with a bang.

What will work, is the balance point spring and a bow thruster working together, so I think that you point reinforces my thinking that for twin rudder boats a thruster goes from being an undesirable complication to a requirement.

John, Good points, I didn’t think about a offshore howling you off. I do agree that a bow thruster is probably your only option.. Well, next to adding a third rudder or removing the two in lieu of one big one. I don’t think any of them is cheaper than the other once said and done.

Hi Ronnie and John,

I think that the magic spring line will still work well even without the help of prop wash. The thing that pulls the boat against the dock is the spring line itself (with a single rudder you can cheat and use prop thrust instead if the spring line has no angle to it) so the keys are getting an appropriate load on the line and having it pull in the correct direction. To get a load on it, you simply need to power against it, the more throttle you give it, the higher the load will be.

Getting the direction of the load correct is dependent on where each end of the line is attached to. Lines can only react tensile forces in line with them so the line needs to have an angle to the dock so that it can react your engine thrust and also pull the boat towards the dock. Too steep an angle and the stern will end up too far in, too shallow an angle and it will end up too far out (where the line is fore and aft also has a similar effect). For boats with shape like Morgan’s Cloud, you get a decent angle with a short spring that leads to a cleat right there on the edge of the dock. If the boat carries her beam aft, you might need to lead it to the far side of the dock finger to get some angle. Unless the boat is quite large, getting the exact right angle is not that big of a deal, you should be able to deal with a 10 or even 20 degree misalignment using fenders and by pulling on the bow and stern lines. The point is that you can hold yourself stationary indefinitely in approximately the position you want to be in while you sort out the other lines.

Even in the case where you have wind blowing hard off the dock and you start perpendicular to the dock stern-to, you should be able to get into place with this method, it will just take a minute. Because the line will be coming from the rail rather than centerline, there will be a torque when you motor ahead that will turn the boat so that the thrust will start to push the boat along the dock causing the spring line to pull you against it. In this extreme case, it is likely you won’t come in parallel so wide fender placement is critical.

That all makes sense and will be of comfort for twin rudder boat owners, thanks.

That said, I’m pretty sure that the “magic spring” will not be nearly as easy to use without prop wash on the rudder, as you allude to with your comment about fender placement.

In thinking about it, I’m guessing that the worst situation may be with the wind blowing hard onto the wharf. In this case with a single rudder we just steer hard away from the wharf to counteract the tendency (on most boats) for the bow to blow in and hit the dock hard as the boat comes in. On a floating dock this might not be too bad since the bow can land on a well placed fender, but on a high fixed dock the pulpit will be at risk and here, on a twin rudder boat, a burst from a bow thruster will be useful.

(I wouldn’t recommend a bow thruster for just this use, but given that twin rudder boats don’t have the benefits of prop wash in many other situations I guess I would stick with my recommendation in the post above.)

Hi John, Perhaps I missed it, but was hoping to find some hints in this book on docking related to a wind + current situation. We experienced this the other day and I made rather a mess of it…That’s no anchor roller, it’s a battering ram.! Wind was from ahead, current from astern , dock on port side. On retrospect i probably should have faced into the 2 kt. current rather than the 13 kt wind… thanks!

You remind me that I need to get back to this Online Book, probably be this summer.

On current, the key tip is that you can’t think of it like the wind. Unlike the wind, current does not pivot the boat in any way, but rather moves the entire boat. A good way to think about it is a model boat on a table with two people carrying the table: the motion of the table is the current.

So yes, in that situation it would be better to stem the current and have the wind on the stern. In fact, as I explain earlier in this online book, contrary what may people believe, it is actually far easier to dock a boat with the wind on the stern.

Twin rudders for bluewater cruising

Having been a proponent of twin rudders for well over a decade, Rob Humphreys Design has a wealth of experience with the arrangement through a range of boat types, from the rather esoteric world of Open 60s and Volvo 70s through to moderately heavy cruising yachts.

Our knowledge of what to do and how to do it has been partly theoretical, partly intuitive and – through feedback from our boats – partly empirical. However, it is only very recently that we have had the opportunity to really quantify the benefits. This came through an exhaustive tank testing session on behalf of the new  Oyster 885 , which was commissioned by Oyster on the basis it would not only benefit the development of the 885 but also the rest of the  Oyster range .

In the early design brief discussions last year on the Oyster “PC” as it was code-named, the Oyster New Product Development team and I sat down and ran through their ideas for how this new yacht should fit into the range. The conclusion was a yacht with moderate beam, balancing the requirements of interior volume with boat speed, a mast further aft to provide a powerful blade jib for easy upwind sailing, and room for four owner/guest cabins in a hull length of “no more than 20 millimetres short of the LY2 MCA 24 metre rule”.

It was clear that this was going to be a bit of a sea change for Oyster. We all felt it would be helpful to have tangible reference information for those owners trying to understand the shift from a skeg-rudder to the twin rudder form for this exciting new model.

In fact our testing session set out to do more than just this because we also used the opportunity to let the spade rudder have it's say, just for some form of completeness. We have often been asked why Oyster has tended to steer clear of spade rudders and the answer has more to do with potential vulnerability than any disrespect for it's potential qualities. As any Oyster owner knows, a bluewater cruising yacht has to be accomplished in a number of different ways, and one of the lower profile requirements has to be an ability to slide backwards against a Mediterranean harbour wall without necessarily endangering the steering gear. One paradox of success for Oyster is that with so many boats out there, if it is possible to do something then it has usually been tried. In this case, with three SuperShoal twin rudder Oysters already on the water, the expression ‘tried and tested’ comes to mind. A spade rudder, whatever its qualities in other respects, is not quite as bomb-proof as a rudder hung off a full-depth skeg.

In our tank testing we were focusing our attention on a fully-pressed up set of sailing conditions, with the boat heeled over to 20 degrees and sailing at nine knots, with a variety of leeway angles and load conditions. Separately we had commissioned North Sails to run their proprietary CFD (Computational Fluid Dynamics) panel code ‘Flow’, to determine the exact three-dimensional centres of pressure that are relevant to Oysters, so that we could keep an eye on what was happening to the balance of the boats.

We tested a lot of other things as well, but the rudder testing was most interesting and was totally supportive of all that we had learnt to be true in the field. For a given side force and leeway angle the skeg rudder and the spade rudder were in a roughly similar ballpark, whereas the twin-rudder equivalent was in another world altogether. For example, with the twin rudders set to just two degrees to the flow, the spade rudder needed to be at over six for an equivalent moment, and the skeg-hung rudder at eight – all for the same yaw moment.

Put another way, the leeward twin rudder provided four times as much force than a skeg rudder!

Much of the distinction comes from the fact that the twin rudders are operating in clean water whereas centreline rudders – of whatever denomination – are operating in a disturbed second-hand flow coming off the keel. The result is a much more satisfying steering experience and at the same time a significant reduction in resistance – so more speed.

From our perspective, twin rudders represent a huge benefit and Oyster owners will really appreciate this development too as soon as they have the wheel at their fingertips. But what’s also interesting is that the system fares a lot better in terms of potential reliability, especially against the spade rudder. The blades are significantly smaller and more lightly loaded, and the span is considerably shorter, making it almost impossible to damage the steering gear when reversing into a quay. And of course, with two rudders rather than one, there is an obvious increase in the level of redundancy. Unlike some twin-rudder installations, the arrangement we have for Oyster means that even assuming the worst-case loss of one rudder it would still be possible to sail the boat on the compromised tack, albeit with reduced canvas.

All in all we learnt nothing new in a qualitative sense; but in quantitative terms it was certainly an eye-opener, not just for me but also for the Wolfson Unit who had not previously run such a benchmarking comparison.

With twin rudder installations already in action on Oyster 82s and an Oyster 655, and now specified as standard on the new  Oyster 885 , in addition to being available on the SuperShoal versions of the 54, 575 and 625, we see their use spreading through to the standard keel yachts. Watch this space for the next new model!

Read about the hotly debated topic of the motor yacht vs the sailing yacht  here.

Sign up to our newsletter

Be the first to hear about new launches, exclusive events and all things Oyster

© 2024 OYSTER YACHTS

OYSTER WORLD RALLY

The Oyster World Rally 2028-29. Embark on the sailing adventure of a lifetime. Entries open 18 June 2024

The new 565 Series II

The pursuit of perfection continues

Explore the benefits that come with taking ownership of a new Oyster, and becoming part of the family

GRAND TOURING

Elaine bunting reviews the new oyster 885gt.

LUXURY CHARTER

Experience exhilarating sailing, luxury and style on an oyster charter. personal, exclusive and uniquely oyster.

Join Oyster Brokerage at the Palma International Boat Show, 25-28 April 2024. Book your tour today

Oyster world rally.

Entries open for the Oyster World Rally 2028-29. Embark on the sailing adventure of a lifetime

Follow the Oyster World Rally 2024-25 fleet live

Winner of European Yacht of the Year 2023. She sets a new 50 foot bluewater benchmark, offering a stunning combination of sailing performance, comfort, safety and luxurious living space.

Heralding a new generation of Oysters, this 60 foot bluewater cruiser is a sailing yacht for all oceans. Practical and well-provisioned for long distance sailing or cruising in coastal waters.

The much-anticipated Oyster 595 is well-proportioned and extremely versatile. Offering exciting, customised build options with no compromise, she is capable of great things.

A versatile sub-70 foot sailboat offering the perfect balance of size and practicality. She can be sailed shorthanded effortlessly or take a full crew and up to eight friends and family.

This long range 75 foot cruising yacht is designed for very big adventures. A joy to sail yourself, she also boasts dedicated crew quarters.

Oyster 885SII

An exhilarating 90 foot sailing yacht, delivering comfort and safety with uncompromising performance. She is capable of taking you anywhere in the world effortlessly, in luxury and style.

First name *

Last name *

Phone number *

Country/Region *

Attach CV *

Attach covering letter

Current occupation

LinkedIn profile

• OC Wally Cento
• 84 Mini Maxi
• IMOCA Open 60
• Consultancy Services
• 30m Blue Water Cruiser
• 25m Explorer Yacht
• 24m Fast Cruising Catamaran
• 23m Performance Cruiser
• 20m Explorer Yacht
• 20m High Performance Cruiser
• 18m Blue Water Cruiser
• 15m Performance Cruiser
• 15m Explorer Yacht
• 12m Explorer Yacht
• Multihull Design
• 18m Explorer Yacht
• 40m Blue Water Cruiser
• 40m Cruiser Racer
• 33m Performance Cruiser
• 30m Wally Cento
• 24m ORCsy Racer Cruiser
• 24m Day Sailer
• Carbon Component Design
• Yacht Performance Development
• CFD and Model Testing
• Twin Rudder Steering Systems
• Custom Deck Hardware
• Modifications and Refit
• VPP Routing and Sail Analysis
• Classic Yacht Refit & Optimisation
• Naval Architecture
• Engineering
• Rudder Design
• Brokerage Services
• 'Seahorse Magazine' #192
• Lucent #180
• Influence #171
• 'Eora' #169
• 'The Three Brothers' #168
• 'Edenred' #165
• 'BHB3' #163
• Polka Dot #154
• 'Teata' #148
• 'Kite' #144
• ‘Sensei’ #131
• 'Sabre II' #93
• French Pineapple #79
• 'Letto Di Pletto' #47
• 'Mowgli' #41
• 23.8m Ultime Trimaran
• 20.7m Orma Trimaran
• 18.28m Orma Trimaran
• 16.75m Cruising Catamaran
• 16.1m Cruising Catamaran
• 12.8m Crowther Shockwave Catamaran
• 9.1m Seacart 30 Trimaran
• 26.3m Aluminium Sloop
• 22.38m Aluminium Classic Yacht
• 21.0m Steel Schooner
• 21.0m Aluminium Cruising Ketch
• 20.0m Aluminium Explorer Yacht
• 20.0m Luca Brenta Racer Cruiser
• 19.6m Aluminium Bluewater Cruiser
• 18.8m Custom Steel Sloop
• 18.23m Mylius Racer Cruiser
• 16.0m Sly Cruiser Racer
• 14.5m Aluminium Cruising yacht
• 13.87m Wooden Motor Sailer
• 11.6m Classic Pilot Cutter
• 25.25m Reichel Pugh Maxi
• 18.28m IMOCA 60 One Planet
• 18.28m O Canada IMOCA Open 60
• 18.28m Come in Vendee Open 60
• 18.23m Mylius FD Racer Cruiser
• 15.84m TP52 Racing Yacht
• 15.25m Pegasus Open 50
• 10.89m Figaro 3
• 10.1m Figaro 2
• 14.5m Aluminium Cruising Yacht

What’s the best rudder design and why are Sirius Yachts so easy to manoeuvre?

If you’ve seen the videos of our deck saloon sailboats manoeuvring effortlessly in the tight space of a marina, you may wonder how we can make it look so easy. The simple answer is that it looks easy because it is easy. Years of practice are absolutely not required as we prove on every test sail; after 10 minutes of simple instruction anyone on board who is more than eight years old can manoeuvre a Sirius with the same confidence. Part of the reason our yachts are so easy to manoeuvre is rudder design, combined with the position of the propeller.

A rudder needs to work well for both sailing and motoring, but many believe a rudder can only be good for sailing or motoring, not both. Most boatbuilders nowadays just focus on producing a rudder that’s efficient for sailing, but it doesn’t have to be one or the other. You can indeed have both. We even have a solution for hard-to-manoeuvre twin-rudder yachts, which have no prop wash to steer with.

The three rudder options we offer

We offer three rudder options. The first is a single, partially balanced spade rudder with a skeg for added protection. This is the standard setup on all our fin-keel yachts and also on the twin-keel versions.

On all our lifting keel yachts we use twin rudders because when the yacht is dried out, the height from the hull to the sea bed won’t allow enough span (rudder height) to give good control under sail. Instead of one deep rudder, we use two shorter rudders, angled outwards at the bottom so that at any heel angle one rudder is always fully immersed and close to vertical for optimum performance. Twin rudders also give the security of a wider support base when the boat is dried out.

The third option is three rudders: the standard twin rudders as above plus a small, central third rudder whose sole purpose is to improve manoeuvrability under power, especially from a standstill and at low speed.

The best rudder design for motoring

Let’s first look at how our rudders are optimised for use under power. If we were making a motorboat, the rudder would have little or no area forward of the rudder stock. It would only need to be the height of the propeller, and the distance between rudder and propeller would just be a quarter to half of the propeller’s diameter. Most motorboats are steered entirely by prop wash (the flow of water from the propeller passing over the rudder). As mentioned above, our twin-rudder boats also have the option of a smaller, central third rudder. Like a powerboat rudder, it steers the boat by efficiently deflecting prop wash and also directing a laminar current onto the two rudders.

Life isn’t so simple for our single rudder designs; they have to be equally efficient under sail and power. To get maximum manoeuvring efficiency from prop wash we locate the propeller at an optimum distance from the rudder, so that the cone-shaped, moving mass of water is the same height as the rudder when it hits it. The positioning has to be precise. The rudder blade needs a large surface area for efficient performance under sail, and if it’s too close to the propeller there will be a lot of pressure on the rudder, making it heavy on the helm with lots of vibration under power. If it’s too far away from the propeller, the energy of the prop wash dissipates into the surrounding water before it hits the rudder. One reason we prefer saildrives, rather than shaft drives, is that they allow us to fit the engine in what would typically be an aft cabin (this is one reason why the aft cabin of the Sirius 40 DS is transverse), which puts the propeller in an optimal position and gives the owner an excellent mid-cabin plus a workshop. We do also fit shaft drives to some of our yachts, but they generate more noise and vibration and this moves the engine a bit further forward. You can have whichever drive you prefer.

When a yacht is motoring, the area of rudder blade forward of the post (or stock) is doing the most work. It’s under the highest pressure from prop wash and helps to deflect more water over the high-pressure side of the rudder. The area forward of the stock also helps to balance the helm. Without it, the rudder would require more effort to turn. But if there is too much surface area forward of the stock, the rudder will become unbalanced and twitchy under sail – the helm will require constant attention, which is clearly a bad thing on a cruising yacht. It’s all about striking the right balance (if you’ll excuse the pun) between a rudder that provides a good steering response and one that is not hard work to turn at high speed.

The water pressure is highest at the point where the prop wash hits the hull, and because our propeller is closer to the rudder than on most other boats, a lot of pressure is exerted on the top (or root) of the rudder. One way to avoid it experiencing too much pressure is to remove the area forward of the stock where the pressure is highest. We do this with the addition of a skeg. Under power, the skeg absorbs the water pressure and directs the flow of water over the rudder. It acts like the wing of an aircraft and the rudder is the control surface on its trailing edge – if the whole wing of an aircraft were to move in flight it would be very unstable, it’s the same principle. The skeg stabilises the flow of water, so by the time the water hits the rudder there is minimal turbulence. This translates into less movement and vibration of the rudder under power. Adding a skeg is an expensive complication in the production process, that’s why it is rarely seen in production yachts. Twin-rudder yachts don’t suffer the same way because the turbulent water from the propeller passes cleanly between the rudders, and in our triple-rudder design the third rudder is small enough and designed not to be affected.

The best rudder design for sailing

Our yachts are not just designed for party tricks in marinas, they are also designed to sail well. So any rudder design we use has to work at least as well, if not better, for sailing as it does for motoring. To achieve this the rudder blade must be deep, so when the yacht heels there is still enough of the rudder in the water to maintain control. Under sail, it’s the trailing edge of the rudder that is doing the work and is under the most pressure.

Why twin rudders have become popular

There is a trend for yachts to carry their maximum beam a long way aft to enlarge the aft cabins. Sirius yachts don’t need the aft cabins to be the master cabins because the accommodation is on two levels, and we prefer to keep our cockpits low down for greater comfort in rough seas. For single-rudder boats, the problem with a broad, overly buoyant stern (apart from excessive heeling and being vulnerable when docking) is that as the boat heels, the root (top) of the rudder is lifted out of the water. If the top 30cm (1ft) of a 1.3m (4ft 3in) rudder blade comes out of the water, more than a quarter of the blade’s effectiveness is lost. The top quarter of the blade becomes useless and the rest of the blade is operating in less dense water. The angle the blade is working at also makes it less effective and when under pressure it will ventilate: a vortex of air swirls down one side of the rudder, which loses its grip in the water, causing a sudden loss of control as the boat rounds up into the wind. To stop that happening, the crew needs to play the mainsheet constantly in gusty winds, which is exhausting if you’re sailing long distances, and the yacht will need to be reefed (and unreefed) more often.

To avoid this effect, many yachts have twin rudders that are angled outboard on each side of the stern. As the yacht heels, the leeward rudder is pushed into deeper, denser water and becomes vertical, making it more efficient. Twin rudders tend to be narrow-chord with a short span (short and skinny) and they must be set well apart to make them efficient while sailing. The problem is that there’s no prop wash over the rudders when manoeuvring in harbour, so unless the yacht is moving relatively fast through the water you have no steerage. When the yacht is stationary, she cannot be turned by applying helm and giving the engine a burst of power. Only when there is water passing over the blades at a speed faster than is prudent in confines of a marina will the yacht start to turn. One way to overcome this trait is to fit a retractable stern thruster in addition to the bow thruster, but they come at extra expense and need to be operated simultaneously with the rudder and engine and bow thruster, as well as using more power. Also, they take up space inside the hull and they’re something else for debris to catch in.

Sirius yachts don’t have fat aft quarters, they have a more balanced hull form for better all-round performance and comfort and safety at sea, so we don’t need twin rudders or stern thrusters – a single rudder works well. When a Sirius heels, the rudder blade is deep under water and remains fully immersed.

The reason we use twin rudders on some of our yachts

We do, however, use twin rudders for a different reason on our lifting-keel and twin-keel yachts, which are designed to dry out. With a draught up to 75cm (2ft 5in), a single rudder wouldn’t have a long enough span to work properly. Where we fit twin rudders, they have a relatively long chord (wide blade) and because our hulls are only moderately wide at the stern, the rudders are quite close together. A burst of power from the engine can be diverted by the rudders, creating a turning effect – not as much as with a single-rudder boat, but more than most twin-rudder yachts.

We can fit twin rudders on any of our yachts. We offer the option of twin electric drives (for propulsion and power regeneration) and we recommend twin rudders, one behind each drive, to give the very best manoeuvring ability. Not only is the thrust directed over both rudders, the two drives can be powered individually so with one drive in forward and the other in reverse she will pivot on the spot.

Construction of the rudder and skeg

As mentioned above, our single rudders have a half skeg that serves many purposes. As well as absorbing the energy of turbulent prop wash at the top of the rudder it also helps direct the water passing onto the rudder blade while sailing. It boosts the efficiency of the rudder and also protects it from hitting submerged objects. Inside the skeg is a stainless-steel structure that is through-bolted and bonded to the hull. We don’t hang the rudder off the skeg, though; three bearings would create a rudder that is harder to turn when heeling and wear out the bearings faster. Instead, we use two self-aligning bearings. A well-designed, strong rudder design doesn’t need a skeg for support, only for protection.

A rudder to dry out on

We use an alloy stock in our rudder blades that is optimised for seawater and strength. The blade is built in two parts, laminated onto the stock on the inside, and filled with closed-cell foam then laminated along the leading edge. On our yachts that are designed to dry out, the rudder has a wide foil on the tip to give a larger surface area for the rudder to rest on. When our twin-keel yachts dry out on concrete or any other hard surface, the rudder will be about 80mm (3in) off the ground and she will sit happily on her keels – we wanted to see how stable, so we had 12 guys jumping up and down on the stern and they were unable to get her to move.

On softer surfaces, like sand and gravel, the keels sink in by about 2-5cm (1-2in). Our boats’ longitudinal centre of gravity is slightly aft of amidships, so the stern tends to sink in a bit further. The wide foil, or foot, at the tip of the rudder spreads the load and prevents the rudder blade from sinking in. The rudder has a Delrin sheave to transfer the weight onto the hull and it is designed to provide a stable tripod stand for the hull. The rudder is deliberately a little shorter than the keels for added safety – when you run aground while feeling your way into your perfect spot to dry out, the keels will touch the bottom before the rudder does. On our lifting keel models, the twin rudders support the stern of the boat so she will dry out upright.

General Manager – Torsten Schmidt SIRIUS-WERFT GmbH Ascheberger Straße 68 24306 Plön/Holstein

Fax: 0049 – 4522 – 744 61-29

Receive regular updates from Sirius Yachts

Subscribe to our email newsletter

Privacy Overview

• Types of Sailboats
• Parts of a Sailboat
• Cruising Boats
• Small Sailboats
• Design Basics
• Sailboats under 30'
• Sailboats 30'-35
• Sailboats 35'-40'
• Sailboats 40'-45'
• Sailboats 45'-50'
• Sailboats 50'-55'
• Sailboats over 55'
• Masts & Spars
• Knots, Bends & Hitches
• The 12v Energy Equation
• Electronics & Instrumentation
• Build Your Own Boat
• Buying a Used Boat
• Choosing Accessories
• Living on a Boat
• Cruising Offshore
• Sailing in the Caribbean
• Anchoring Skills
• Sailing Authors & Their Writings
• Mary's Journal
• Nautical Terms
• Cruising Sailboats for Sale
• List your Boat for Sale Here!
• Used Sailing Equipment for Sale
• Sell Your Unwanted Gear
• Sailing eBooks: Download them here!
• Your Sailboats
• Your Sailing Stories
• Your Fishing Stories
• Advertising
• What's New?
• Chartering a Sailboat
• Sailboat Rudder

Making a Sailboat Rudder for s/y Alacazam

It's not enough just for a sailboat rudder to steer the boat effectively, it should also contribute to the keel's job of providing lift to windward, and for it to do this it must be designed as a hydrodynamic foil.

Of course a rudder doesn't have to provide lift, but it's a wasted opportunity if it doesn't.

As with an aircraft's wing, to develop lift the sailboat rudder must have water flowing over its leading edge at an angle of attack.

Fortunately for us sailors, the pressure of air on the windward side of the sails, pushes the boat bodily off course slightly and it's this leeway that provide the angle of attack - or angle of incidence- that enables our keels and rudders to provide lift.

But What Type of Sailboat Rudder would be Best for Alacazam ?

First, we considered twin transom-mounted rudders. The usual argument for twin rudders is:

• as the boat heels, the leeward rudder is more deeply immersed and provides better control, and
• the boat, resting on the keel and two rudders can dry-out upright.

But in the end we decided against the twin rudder arrangement because:~

• with Alacazam's deep draught (7 feet, or 2.2m) the twin rudders wouldn't be deep enough to achieve the drying-out upright benefit, and
• the mechanical complexity of tiller steered twin rudder system went against one of our key design principles - keep it simple, and
• with no propwash flowing over the rudders, manoeuvring under power in tight situations would be a little too interesting for my tastes.

So the conventional single rudder approach it was to be. But what type of sailboat rudder?

A Transom-Hung Rudder

We liked the simplicity of this arrangement, but it didn't suit Alacazam's hull design at the stern. We wanted a sugar-scoop design with a bathing platform to allow easy access from the dinghy which ruled out a transom hung rudder. Similarly, it meant that mounting the servo-pendulum self-steering gear would be unnecessarily complicated.

Spade Rudder

The spade rudder is the most efficient of all sailboat rudders, which is why you're unlikely to see any other design on racing yachts.

The absence of a skeg means that all of its area is used to apply a turning force to the hull, minimizing wetted area and associated drag.

The area ahead of the stock helps to balance the rudder, making life easier for the helmsman.

But it's not the most robust design, being entirely dependent on the strength of rudder stock to resist impact damage.

Theoretically it's just a matter of engineering, but high performance spade rudders just aren't thick enough to incorporate a rudder stock of sufficient diameter for ultimate security.

Skeg-Hung Rudder

Other than those rudders hung on the following edge of long keels, the skeg hung rudder - supported top and bottom on a full length skeg - is the most robust design.

Without a portion forward of the stock, there's no balancing force to take the load of the helmsman's arms - so loads can be quite heavy in some designs.

Nevertheless, it's a very popular design for offshore cruising boats.

Semi-Balanced Rudder

This design of sailboat rudder is something of a compromise between the spade rudder and the full skeg rudder.

Supported at its mid-point by a half-depth skeg, it benefits by the area forward of the stock, below the skeg.

This applies a balancing force as the rudder is turned making the steering lighter than it would otherwise be. And it was this design we chose for Alacazam's rudder.

Making Alacazam's Rudder

A typical productions boat's rudder is likely to have been fabricated as shown here, with two GRP mouldings 'clamshelled' around a foam core.

Not the most reliable arrangement you might think - and you'd be right.

We wanted something a little more robust for Alacazam's rudder.

But first, the rudder stock.

We fabricated this from a 2" (50mm) diameter stainless steel solid bar and welded on flat stainless tangs that would be embedded within the rudder.

The Admiralty Bronze casting will eventually connect the rudder to the skeg.

With the rudder stock fabricated, we began the construction of the rudder core.

It was made up from half inch (12mm) marine ply sheets, cut to shape and incorporating cut-outs for the tangs, screwed and glued together.

The rudder and skeg was built up as a single unit at this stage.

The rudder design software generated coordinates for various stations along the rudder, and we used these to cut templates so that we could get the shape right.

Shaping the rudder profile was done by hand, initially with a plane to remove the excess, then with a file and diminishingly coarse grades of sandpaper.

Once the rudder profile matched the appropriate template we removed the section that would form the skeg.

Next, the rudder was fitted to the stock with any gaps between the tangs and the ply taken up with high-strength epoxy 'gloop'.

Finally both the rudder and the skeg were sheathed in several layers of epoxy-glass rovings before being filled and faired with epoxy fairing compound.

Fitting the Sailboat Rudder

The skeg was letter-boxed through a slot cut in the hull, securely braced internally and bonded to it with fillets of high-strength epoxy and epoxy glass rovings.

Inside the hull we had constructed a GRP tube to contain the stock, and the skeg was also bonded to the lower end of that.

The rudder was then securely fitted to the stock via the bronze bearing, and located at the top of the rudder by a stainless steel bearing.

That's it, we now have a very robust and efficient rudder securely attached to Alacazam's hull.

Recent Articles

Wauquiez Gladiateur 33 for Sale

Apr 10, 24 05:40 AM

'Cabo Frio', a Catalina Morgan 43 for sale

Apr 01, 24 08:35 AM

Live Aboard Boats For Sale

Mar 30, 24 07:02 PM

Here's where to:

• Find  Used Sailboats for Sale...
• Find Used Sailing Gear for Sale...
• List your Sailboat for Sale...
• List your Used Sailing Gear...

Building Alacazam...

But why go to the bother of building your own boat?

Copyright © 2024  Dick McClary  Sailboat-Cruising.com

About   Kraken

Find out more about Kraken Yachts. Check out the latest Kraken in-build at our bespoke factory in Turkey or meet the team behind the yachts.

Kraken   Design

Kraken Yachts are the safest blue water sailing yachts in build today. Find out what makes our yachts so special.

Kraken   News

Stay up-to-date with everything Kraken Yachts. See our reviews in yachting magazines from around the world or find out about Kraken Yachts and all things sailing in Ocean Sailor Magazine.

Get more from Kraken Yachts . Watch, listen and read everything about bluewater sailing.

Kraken Yachts

In development, ocean sailor news, genesis of the twin rudder.

• March 7, 2020
• , Ocean Sailor News

‘It’s the ultimate Blue Water design crime’

If you want to go blue water cruising then buy a cruising yacht, if you want to win races buy a racing yacht. A racer-cruiser will never be both the best racing boat and the best cruising boat. That’s because the compromises made are compromises too far when it comes to producing a safe blue water yacht.

My beef isn’t that these boats are bad boats per se it is that they are bad boats when marketed as suitable for world cruising.

This design amalgam now affecting all modern blue water boat builders originate from the popularity engendered by sailboat racing such as The Volvo, The Vendee Globe, and The Jules Verne Challenge.

The evolutionary process has been as follows:

• To lighten construction by using lighter and stronger materials, such as carbon- fibre and a whole variety of aramid materials and alternative construction methods.
• To change the shape of hull and stern so that this lighter yacht can now plane.
• To widen the stern so that increased form stability enables the yacht to carry more sail area.
• To change the shape of the hull to a full delta ‘wing’ style, maximising the ballast ratio to lighten the yacht further and increase the sail area further.
• The payback for that is a stern so wide that, on the wind, a single central rudder is levered half out of the water, losing traction and therefore steerage way. Which leads us to:
• The use of twin rudders, one for each tack so that one is always fully immersed.
• So brilliant, now the boat can plane and sail exceptionally fast.

But hang on, we’re supposed to be cruising, aren’t we?

What has all of that got to do with a safe, comfortable, blue water cruising yacht?

Nothing at all.

However on the boat show stands, families are understandably impressed by cockpits big enough for a game of badminton; apartment-sized aft cabins; and dinghy garages, all features that are very different, and sometimes treacherous, spaces on a rolling, open ocean. 

The boat show sales folk will ask you to slip off your shoes, proffer the glass of Prosecco, then invite you below decks, but it’s below the waterline that counts: hull form, keel and rudder.

What, in my opinion, and in the opinion of many in the marine industry who still remain silent in the press, has occurred is that these design demons are now becoming standard, even with top brands that have, in the past, been synonymous with safe Blue Water cruising. The latest models from builders including Hallberg Rassy, Amel, Oyster, and Discovery, all have twin rudders.

A single spade rudder is vulnerable enough to the hazards of ocean sailing, but two, and what’s more two that are out of line with the keel, is simply asking for trouble.

It’s crazy to think you can sail across the seas and oceans of this world increasingly littered with debris, containers, logs and, thanks to wild life protection campaigns, inhabited by growing schools of whales without risking fundamental damage to one or other of these unprotected steering blades. 

Maybe not this week, perhaps not this month, but as your log clocks up the miles, sure as hell there will be a hazard with your boat’s name on it.

Dick Beaumont

Another sailing expert speaks out

Hallberg-Rassy ‘Gave Away’ Design Pedigree

Leading yacht designers’ Hallberg-Rassy ‘gave away their pedigree’ by switching to bolt-on keels and spade rudders, top yachting expert, Duncan Wells told Kraken News in February. 

Wells, who owns and sails an old-style Hallberg-Rassy with a long keel and skeg-protected rudder, said: ‘We all know spades can fall off. If you are going to punch through the rough stuff at sea then you want something substantial beneath you. The trouble is, these days, they all want to go faster…much faster and they gave away the pedigree when they made that change.’ Wells was delivering one of his popular Stress-Free lectures on boat safety at the Cruising Association HQ in London’s Limehouse. 

Share this post

Are you subscribed, be the first to know when we release new content, sign up today so you don't miss a thing, more from ocean sailor.

There’s plenty more to read at Ocean Sailor. Check out some more articles…

STORMS, CALMS AND A WILD WILD COAST

The Dragon Roars

The Ionian Islands

Storm for a Teacup

© All rights reserved Kraken Yachts 2024

Designed & created by Oncrowd

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.

• Forums New posts Unanswered threads Register Top Posts Email
• What's new New posts New Posts (legacy) Latest activity New media
• Media New media New comments
• Boat Info Downloads Weekly Quiz Topic FAQ 10000boatnames.com
• Classifieds Sell Your Boat Used Gear for Sale
• Parts General Marine Parts Hunter Beneteau Catalina MacGregor Oday
• Help Terms of Use Monday Mail Subscribe Monday Mail Unsubscribe

Twin rudder problem

• Thread starter Dennis Thomas
• Start date Feb 19, 2018
• Beneteau Owner Forums
• Ask A Beneteau Owner

Dennis Thomas

Hey anyone, I have a 311 with twin rudders. I am relatively certain that the starboard spade is out of kilter. ie; I cannot turn to starboard - when I do there is quite the circular motion of water coming off the stern. I took a look below the cable hatch today. It looks ship shape. Is the adjustment below the water line? Any suggestions based upon practical experience appreciated. I hope to fix the issue before the next race - 4th of March.  

Weird. On every dual rudder boat I've even owned or been on, one rudder is directly controlled by the wheel/tiller, and the other is slaved off the first with a tie-rod. If one is messed up or jammed normally the other one is too. It is possible that your tie rod is loose, so you would have authority over one but not the other. I'd start there. There is no below waterline adjustments.  

OK, I am wading in here with some trepidation. A friend who races twin-rudder boats tells me the toe alignment for the rudders is critical. I think he said they are aligned with the front of the keel. However, a call to the manufacturer is certainly in order on that. The same guy said alignment was checked before all the races but we are talking global big event boys here.  

Didn't the Beneteau 311 use a Whitlock wheel?  

Will Gilmore

Could the rudder be bent? Damage from lift or hit something? Tangled crab pot line? Shaft twisted in the bearings? Damage from dry storage? -Will (Dragonfly)  

Rick D said: OK, I am wading in here with some trepidation. A friend who races twin-rudder boats tells me the toe alignment for the rudders is critical. I think he said they are aligned with the front of the keel. However, a call to the manufacturer is certainly in order on that. The same guy said alignment was checked before all the races but we are talking global big event boys here. Click to expand

Jackdaw said: They are pretty much bore-sighted down the centerline. They are canted OUTWARDS however, so when at optimal heeling angle the leeward rudder is vertical in the water. This aids steering greatly because the rudder is just turning, and not trying to lift or 'dive' the boat. This is the big reason why they are more stable, and why single rudder boats spin-out when heeled hard over. View attachment 146741 They do however need to be in alignment. The only way permanently mounted rudders can come out of alignment is of the tiebar slips. Click to expand

I assume the tie bar is adjustable for toe in?  

Rick D said: I assume the tie bar is adjustable for toe in? Click to expand

CaymanMom said: Hello , Question to this group please, twin rudder 311 tie bar (tie rod) ends are plastic, one of mine broke off and we are replacing with steel, is there any"feature of function" that Beneteau would have made these in plastic? Like for breakaway? I am being told NO, solid steel would be better design, but asking the forum to chime in please !! Thank you much Click to expand

• This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. By continuing to use this site, you are consenting to our use of cookies. Accept Learn more…

• Member Login
• About Membership
• Membership Levels
• Global Access
• Embark Mobile App
• About Ownership
• Ownership Benefits
• Ownership Opportunities
• SailTime Marine Financing
• Base Locations
• Target Bases
• About SailTime
• Start Your Own Business
• SailTime Brochures
• Articles & Media
• Request Info

Beneteau Oceanis 38.1

The perfect combination of exhilaration and comfort.

The Beneteau Oceanis 38.1 is the perfect combination of exhilaration and comfort, featuring an aerodynamic, innovative hull paired with a spacious and inviting living area.

The cockpit features all-lines-lead-aft, winches accessible from both the helm and cockpit, a fold-down swim platform with shower, and a large twin-leafed table with excellent storage. The plumb bow, full-length hull chine and wide beam creates superior stability and exceptional high-performance sailing. The fractional rig sail plan combined with the angled twin rudders create a well-balanced sailboat in all wind conditions.

The Oceanis 38.1 is perfectly sized for a day of sailing with friends and family yet roomy enough for a memorable weekend trip away. The 38.1 is offered in two and three-cabin models with a long list of standard features and options from functional to high-end luxury. The spacious interior offers two configurations, the “L Galley” and the “Long Galley,” plus a choice of Alpi mahogany or blonde oak wood finishes.

Take a Tour

In designing the Oceanis 38.1, Beneteau partnered with marine industry leaders, choosing a Yanmar saildrive and a full electronics package from B&G including autopilot, chart plotters, VHF and stereo systems. The sloop rig and high-tech B&G autopilot can be set to track a course; or self-correct to a wind angle – making this boat a pleasure to sail single-handedly or with a small crew.

With twenty-two Beneteau 38.1 vessels in the SailTime Fleet, each equip with the perfect option package for your local sailing conditions and is outfitted with an upgraded anchor, extensive safety gear, a well-stocked galley, barbecues, and everything you need for your next sailing adventure.

Now accepting this model at bases nationwide

Interested in this specific boat model fill out the form below to unlock special pricing .  achieve the dream of boat ownership with sailtime today.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Available Locations

Southwest Florida Fleet

3190 Matecumbe Key Rd

Punta Gorda, FL 33955

San Francisco Bay Fleet

SailTime San Francisco Bay

San Francisco, CA 94608

San Diego Fleet

2040 Harbor Island Drive, Ste 104

San Diego, CA 92101

Portland Fleet

260 NE Tomahawk Island Drive

Portland, OR 97217

Orange County Fleet

201 E Coast Hwy

Newport Beach, CA 92660

Los Angeles Ventura Fleet

13555 Fiji Way

Marina del Rey, CA 90292

Houston Fleet

1500 Marina Bay Dr, Pier 11 Building 122, Ste B

Kemah, TX 77565

Chicago Fleet

3119 S. Route 31

Crystal Lake, IL 60012

Annapolis Fleet

105 Eastern Ave, Ste 102

Annapolis, MD 21403

Boston Fleet

Massachusetts

ONE Marina Park Dr

Boston, MA 02210

• 877-SAILTIME
• [email protected]
• Request a Brochure
• Partners & Vendors
• Articles & Media Coverage
• SailTime Fleet
• SailTime University
• Accessibility

4 Rudder Types for Sailboats

Last Updated by

Daniel Wade

June 15, 2022

A rudder is an ancient piece of technology that people still use to steer sailboats today. Modern sailboats use many different types of rudders.

If you turn the rudder to the left, the stern will turn right, and vice versa. You can use either a steering wheel or a tiller to move the rudder. Not every type of boat has the same kind of rudder, nor should every boat - different boats need significantly different rudders.

There are several different types of rudders in common use. Sailboats use full keel rudders, spade rudders, outboard rudders, and skeg-mounted rudders, plus variations on each type. What type of rudder is best depends on the shape of the hull and the boat's size.

Table of contents

Different rudder types and their advantages

Full keel rudders.

Many sailboats have a full keel rather than a fin keel, which requires a particular type of rudder. A full keel is the standard type of keel, or flat blade at the bottom of a sailboat. A full keel is designed for stability, not speed - it can keep you safe in rough water.

A generation or two ago, nearly all cruising boats had full keels. However, this is no longer true. Many customers today prefer fin keels, which are designed with speed rather than stability in mind.

A fin keel is smaller than a full keel and shaped differently. Fin keels are more popular today because many sailors today never go far from the coast. If you are near the coast, fin keels are relatively safe.

With a full keel sailboat , the rudder appears to be part of the keel. It is attached with a hinge and looks like a continuation of the keel. There may be a hole between the keel and the rudder, where the propeller is, although not all boats use this design.

What is the advantage of a full keel rudder?

A full keel rudder is strong and protects the boat from harm. A full keel rudder helps a boat survive a storm. Any debris floating by will not snag on a full keel rudder as it will snag on some other rudders.

Do full keel rudders have any disadvantages?

It is harder to move a full rudder than to move other types of rudders. Water flowing by the boat puts a great deal of pressure on a full keel rudder and makes the rudder hard to move. It takes a lot of force to push the rudder against the water moving past the boat.

Spade rudders

Spade rudders are for fin keel boats rather than full keel boats. A spade rudder sticks straight down into the water. A spade rudder can rotate left or right with a rudder post that extends into the hull.

Advantages and disadvantages of spade rudders

The most obvious advantage of the spade rudder is that it can be part of a fin keel boat. A full keel rudder requires a full keel - you could not attach a rudder of this type to another type of boat.

It is also not nearly as difficult to turn a spade rudder as it is to turn a full keel rudder. The water does not put all of its force on one side of the rudder, so it does not take as much force to turn it.

One disadvantage is that debris floating in the water can get caught on a spade rudder. Spade rudders are more delicate than full keel rudders in many ways. Debris can damage a spade rudder.

A spade rudder can also be damaged by rough water. Large waves may exert enough pressure on a spade rudder that it will break. A large wave can bend the rudder post, and after that happens, your rudder becomes useless.

Outboard rudders

An outboard rudder is not part of the boat's hull and is mounted outside of it, at the back of the boat. Usually, an outboard rudder is not hooked up to a steering wheel.

Instead, it is hooked up to a tiller, which is a steering lever. A tiller can take a bit of getting used to if you are used to a steering wheel, but a tiller is not hard to use. Many sailors prefer a tiller, especially for smaller boats.

Advantages and disadvantages of outboard rudders

If an outboard rudder is damaged, it is not likely to damage the rest of the boat. Since there is no rudder post running through the hull, damage to the rudder usually won't mean damage to anything else as well.

You may also be able to remove and fix a damaged outboard rudder while you are still out at sea. There is no way to remove a rudder that is part of the hull and beneath the boat, but a rudder attached to the boat with hinges may be possible to fix at sea.

Outboard rudders are not necessarily weaker than and can be stronger than other types of rudders. The hinges that hold an outboard rudder in place may be stronger than a rudder post.

In some ways, an outboard rudder is worse than either a spade rudder or a full keel rudder. Unlike a full keel rudder, things like rope floating in the water can get caught on an outboard rudder. Objects floating by can also hit and damage an outboard rudder more easily than they can damage a more durable full keel rudder.

Compared to a spade rudder, the outboard rudder is harder to turn. The water pressure will always be on one side of the rudder; this is not always the case with spade rudders.

Skeg mounted rudders

Skeg rudders are both durable and possible to use on fin keel rather than full keel boats. Skeg mounted rudders are more durable than the spade rudders you usually find on fin keel boats.

Skeg mounted rudders have the same disadvantage as full keel rudders and outboard rudders, which is that they require more energy to turn. The water will put all of its pressure on one side of the rudder. Only spade rudders avoid this problem.

Is a tiller better than a wheel?

Either for inexperienced or veteran sailors, a tiller can work better. With a tiller, you will get immediate feedback. If you turn a wheel, the boat won't turn right away, which can confuse or annoy a new sailor.

The tiller should be long enough, as it is harder to turn if it is shorter. In strong winds, you need a long lever to turn your boat without it taking a great deal of strength.

It is easier to turn a wheel than to turn a tiller, as there is more leverage with a steering wheel. Therefore, wheels are better for larger boats; as a tiller is harder to turn with a bigger boat.

A tiller's advantage is that it is more responsive than a wheel, even though it is harder to turn. The boat will start to change direction almost immediately if you use a tiller. In racing, it is normal to use a tiller because you can change direction more quickly.

How does a rudder work?

A rudder works through water pressure. If you turn the rudder, the pressure becomes higher on one side of the rudder than the other. The rudder then moves toward the side with the lower pressure, which causes the boat to change direction.

When a sailboat turns, it pivots around a point near the middle of the boat. Both the stern and the bow move simultaneously, with the middle of the boat not moving. You have to take this into account while sailing, or else you might swing the end of your ship into another boat.

What is the purpose of the keel?

The keel keeps the boat stable. Without a keel sticking down from the boat into the water, it would be easy for the wind to push the boat around. Without a keel, the wind could easily push you sideways and make the ship much harder to control.

A keel is also weighted. The keel is full of ballast, which is weight that keeps the boat from flipping over. Without ballast, a boat would be top-heavy and unsafe.

Keels are usually made out of the same material as the rest of the boat - if the boat is aluminum, the keel will be as well. The ballast is usually lead.

While full keels are better in rough weather in most ways, a fin keel does a better job of preventing the wind from blowing your boat around. Wind can create leeway, which is sideways movement of the boat. Leeway is most likely if you are sailing into the wind.

Do rudders often fail at sea?

Yes, a rudder failure is one of the more common hazards you might encounter at sea. Not every sailboat has a good, durable rudder. The rudders on cheap boats, especially cheap fiberglass boats, can fail.

The rudder pole should neither be too weak nor too strong. If the rudder pole is too weak, it will bend easily. If it is too strong, it may damage the hull rather than bend, which is even more dangerous.

A rudder has a metal framework inside of it. If the framework breaks, the rudder will become unusable. With a cheaper boat, the metal framework may not be welded together properly.

Make sure you buy a sailboat that has a reputation for safety. Don't buy the cheapest boat you can find - look into whether or not the boat is safe to take out to sea.

Related Articles

I've personally had thousands of questions about sailing and sailboats over the years. As I learn and experience sailing, and the community, I share the answers that work and make sense to me, here on Life of Sailing.

by this author

Learn About Sailboats

Sailboat Parts

Most Recent

What Does "Sailing By The Lee" Mean?

October 3, 2023

The Best Sailing Schools And Programs: Reviews & Ratings

September 26, 2023

Important Legal Info

Lifeofsailing.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon. This site also participates in other affiliate programs and is compensated for referring traffic and business to these companies.

Similar Posts

Affordable Sailboats You Can Build at Home

September 13, 2023

Best Small Sailboat Ornaments

September 12, 2023

Discover the Magic of Hydrofoil Sailboats

December 11, 2023

Popular Posts

Best Liveaboard Catamaran Sailboats

December 28, 2023

Can a Novice Sail Around the World?

Elizabeth O'Malley

4 Best Electric Outboard Motors

How Long Did It Take The Vikings To Sail To England?

10 Best Sailboat Brands (And Why)

December 20, 2023

7 Best Places To Liveaboard A Sailboat

Get the best sailing content.

Top Rated Posts

Lifeofsailing.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon. This site also participates in other affiliate programs and is compensated for referring traffic and business to these companies. (866) 342-SAIL

© 2024 Life of Sailing Email: [email protected] Address: 11816 Inwood Rd #3024 Dallas, TX 75244 Disclaimer Privacy Policy

THE 10 BEST Moscow Boat Rides & Cruises

Boat rides & cruises in moscow.

• Boat Rentals
• Scuba & Snorkeling
• Fishing Charters & Tours
• Water Sports
• Stand-Up Paddleboarding
• Surfing, Windsurfing & Kitesurfing
• Kayaking & Canoeing
• Waterskiing & Jetskiing
• Parasailing & Paragliding
• River Rafting & Tubing
• Dolphin & Whale Watching
• Speed Boats Tours
• Submarine Tours
• 5.0 of 5 bubbles
• 4.0 of 5 bubbles & up
• 3.0 of 5 bubbles & up
• 2.0 of 5 bubbles & up
• 3rd Transport Ring (TTK)
• District Central (TsAO)
• Garden Ring
• District Northern (SAO)
• Good for Big Groups
• Good for Couples
• Good for a Rainy Day
• Budget-friendly
• Good for Kids
• Hidden Gems
• Honeymoon spot
• Good for Adrenaline Seekers
• Adventurous
• Things to do ranked using Tripadvisor data including reviews, ratings, photos, and popularity.

1. Flotilla Radisson Royal

2. CheapRussia Tours

3. Sup-Club

4. Kite School Kiteclass

5. Akvanavt Diving Centre

6. Easy Russia Tour Guide

7. Moscow River Boat Tours

8. Erwin. Reka

9. Diving Center Crocus City Oceanarium

10. SUP Center

11. Lovely Russia Tours

13. Alfa Centr

14. MORE MOSCOW

15. Sup Outdoor

16. Capital River Boat Tours - Moscow Centre

17. Soho Sailing Style

18. Dive-Project

19. Diving Club Divers

21. S-cruises

22. Morskiye Volki

23. Kayak Moscow

24. Diving Center Crocodile

25. Insider Moscow Tours

26. Mosparokhodstvo

27. russian travel and tours

28. windschool.

30. FLOW Moscow

What travelers are saying.

• CheapRussia Tours
• Easy Russia Tour Guide
• Lovely Russia Tours
• MORE MOSCOW
• Insider Moscow Tours
• Flotilla Radisson Royal
• Moscow River Boat Tours
• Capital River Boat Tours - Moscow Centre
• Diving Center Crocus City Oceanarium