Why not put the curvy bits in the water where they can do more good?

chris

Luomanen - 17 April 2013 01:32 PM

Why not put the curvy bits in the water where they can do more good?

chris

I favour the flat bottomed / sharpie hull,
I went on a bit in Scampie #109
http://proafile.com/forums/viewthread/196/P105/#1723

Many modern multihulls of all sizes appear to being built with flatter bottoms. A rounder bottom obviously offers less surface area which is critical at slow speeds but something, and I don’t pretend to know what, may come into play at higher speeds.

What a box shape gives is maximum bouyancy for given draft and or beam. The ply minimum proa has an L:B of 16:1 and is a box. When I was developing the inflatable proa with a little less bouyancy I had to increase the length just to achieve a L:B of 11:1. Now I appreciate that these the extremes and all designs are a a carefull balance of compromises.

For the ply / foam hybrid underwater would be flat panel. For full foam some degree of roundness may be useful even if just to help the skin lay- up.

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