Thursday, December 5, 2013

Paddling Amas


The first time that you have to paddle your sailing canoe can be annoying because the large buoyant ama will sometimes seem to take over the steering unless you are well practised in anticipating it.
The optimum ama shape for paddling and sailing is very different.  The photo above shows a 45' Hawaiian racing canoe rigged for paddling only.  I've drawn in a dotted line along the waterline to show how very little of the ama is actually touching the water when in use. (Click the photo to enlarge)  The ama is also quite short in comparison to the length of the main hull.
An ama like this would not be a good performer under sail not only because of its lack of buoyancy but also how the entry is shaped when it is pushed down by a press of sail.


The above drawing shows the ama and main hull of the Va'a Motu.  The ama is stretched right up to the main hull bow to give the needed buoyancy to prevent a diagonal capsize.  The entry also has very little rocker to make it pierce waves rather than pitch over them.  Constant changes in pitch or "hobby-horsing" plays havoc with the flow over the sail and makes you go slower.

5 comments:

Wade Tarzia said...

That is a nice sailing ama. I want to build something like that for my car top outrigger sailer. How do you estimate its waterline with a "normal" load on it (its own weight plus its share of the weight of cross-beams)? In other words, how would one estimate the needed height of the ama-to-aka attachments?

Chris said...

Interesting. I paddle outrigger canoes and have always wanted to rig one for sail using double amas. I will need to re-think that and also make some observations on how the outrigger sailing canoes in Hawaii are setup.

Anonymous said...

Ah! So does the ama still pull the boat to the ama side? How small of an ama is needed for a 16- 18 foot boat? about how far away from the main hull?

I wish there was more published information on this topic. I have not been able to locate any.

Len

Gary.Dierking said...

I work out the waterline for the big hull with its heaviest load and then try to have the crossbeams level at that point. You don't want the hull leaning away from the ama side with a big load or you may get wet.

Gary.Dierking said...

With the long Hawaiian paddlers, there is very little pull towards the ama because it is so short and the hull so long. Our smaller canoes with big amas have a much bigger force trying to take over. Look at the OC1 canoes to see a variety of paddling amas.