[Paddlewise] Pygmy Coho, multi chine

daveu wrote:
>
There seems to be some feeling that the multichine hull goes a little
slower than the hard chine (less seems).
<

Unless you are assuming rather poor fairing of the joints, this would seem
to contradict the theory and beliefs that seem prevalent in the reading
I've done on (mostly sailing) boats.  A single hard chine is thought to 
generate a larger amount of turbulent drag than several less acute chines
with much weaker vortexes, esp. when pithching in waves.

I haven't sailed or paddled boats that were similar enough in other
respects to judge this, but I have rowed traditional wooden boats that
were fairly close in other parameters, and would attest that when hitting
small, steep waves (powerboat and seaplane wakes), lapstrake hulls
(essential many small, poorly faired chines) are slowed less than plywood
hulls with only one or two chines.

I would expect that the Coho would be a bit faster going to windward, but
the Tern would surf faster coming back downwind.

Mike Wagenbach

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