Tuesday, June 3, 2014

Transoms


 A transom can be very useful on any boat,  where it can provide a convenient mounting for a rudder and even an outboard motor.   But with a long, narrow and pointy ended canoe, the weight  of those things are better placed more amidships where the trim will be less affected.
I must give the credit for this idea to some unknown fisherman from the Cook Islands .  No doubt similar solutions are used on many Pacific islands.  On one of my visits there, I saw a small flat bottomed plywood canoe with an outboard bracket that consisted of a length of 2x4 shoved through two rectangular holes in the sides of the canoe.  Nothing could be simpler or less prone to failure than this.

This Tamanu canoe uses the 2x4 to support the outboard on the ama side and the kick up rudder on the opposite side.  The leeboard should go on the same side as the rudder.


The above drawing shows the structure used on the Va'a Motu design.  The wood piece lashed on top of the gunwales allows more distance between the gudgeons for better rudder stability.


If the canoe is heavily loaded or trimmed down at the stern, the waves can hit the mount.  A thin plywood shield, held on with webbing hinges and a lashing, deflects any spray away from the motor.


On the Va'a Motu I used a fabric spray shield attached with snap fasteners on the outboard motor side.


The Va'a Motu cassette rudder on its mount.

4 comments:

Jim Cummings said...

Gary,

Just bought a 2HP for my Wa'apa. Was pondering a similar bracket opposite of the rudder. Is there any advantage having the rudder and leeboard to starboard and the ama to port?

Gary.Dierking said...

There's no practical reason for either side. Amas are mostly mounted on the left side from some old tradition and the original reason has been lost.

popeye1 said...

Hi Gary,
Can the transom be made removable easily do you think? The transom sticking out will interfere with loading the Wa'apa hulls easily. My other question is the location of the transom. Since the Wa'apa can be assembled to different lengths is it necessary to move the transom for the different lengths? I am near completion of my boat but weather, work and life have kept me from working on it yet this year.

Gary.Dierking said...

For the two or three piece Wa'apa it is better to use the outboard mount that clamps to the crossbeam. Then it won't interfere with storage and can easily be removed:
https://dl.dropboxusercontent.com/u/21351227/IMG_0185.jpg