I'm going to guess it means a flat bottom (for primary stability but hull reacts more to waves from side-on) and the 2 sides slope up and out from there ( helps secondary stability). In cross-section it would be an inverted A with the pointy part / triangle removed. The Nelo 550 is a bit like that in the mid-section I think.
Is it the same as conical?
CrabStick, Perth Western Australia
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