Side Mounted Rudder

Designed and made by Pete Croft

Amongst the most debated topics in the kayaking community is the use of rudders. Without going into the pros and cons of rudders, one of the disadvantages agreed upon by both parties is the increased weather cocking a rudder causes when not in use. Contrary to popular believe, a rudder is not used as an aid for turning but is there to keep the kayak on a straight line. In most scenarios a well designed kayak should not need a rudder and it should only be used when necessary or for long crossings. Unfortunately once the wind increases the blade of a conventional system acts like a small sail thus forcing the paddler to lower it.

An ingenious solution to this problem is to mount the rudder on the side of the hull. As well as removing blade induced weather cocking it also has the advantage of keeping the blade in the water during rough weather and surfing. When catching a wave in a 17 plus foot kayak the stern is above the wave leaving the rudder out of the water and ineffective. By moving the rudder forward of the stern, the blade is in contact with the water for a longer time.

Pete Croft designed this system on one of his Chesapeake 17's. Although unusual to look at, the rudder is effective and fulfils the design requirements. New ideas always seem strange until they are accepted and become mainstream. Don't be put off by an idea just because commercial manufacturers do not use it, this is one of the great things about building your own kayak - you can experiment.

Construction Diagram

Important Notes

The inside of the hull is reinforced by 3 layers of 4.5mm ply. This is to give the pintle mounting screws some purchase and to prevent the hull being holed if the bracket is torn off.

The Spectra control lines are threaded inside 6mm nylon compressed air hose. Spectra is very abrasion resistant, but can cut or wear through soft plastics with ease. The compressed air hose is made from a tough nylon which will prevent this from happening.

On the photo below you can see a large pop rivet on the blade not far beneath the pivot bolt. This stops the blade from flipping up past horizontal, and if surf (crash !!) landings are your thing it is a quite important little detail. The photo at the top of the page shows where it stops at the horizontal level.

Other Considerations

Notice the slight bend in the blade hightlighted in the photo above right. This bend gives a more vertical profile to the water when lowered and keeps the blade closer to the hull when lifted.

The 3cm diameter washers (refer photos above) used were made from the plastic from an old bucket that had failed the drop test. They where cut out using a hole saw.

The exits are sealed with RTV and in theory both tubes are replaceable as long as there is still a rudder line up the middle of them to act as a pullthrough. They both go from the hull exit point by the rudder to a point near the knees, so that any water that gets in winds up the in cockpit.

Review

"The side mount rudder seems to turn the boat well, with only a very small difference in effectiveness between going right or left. It has definitely met the objective of reducing windage-it has NONE, and it is far lighter than the sliding rudder arrangement that the other boat has. As for reduced drag, that is a lot harder to quantify, but the seat-of-the pantsometer says that it is no worse."

If you have any questions e-mail Pete here:- Pete Croft