Originally Posted by danielgoldberg
This makes a little bit more sense to me. I bet you saw the flex a bit higher than at the design waterline. If you were in 4-6 foot seas beating into a stiff breeze, I bet you were heeling a fair amount, which means the topsides were well into the water and feeling the effects of the sea. I still find it odd that you would get oil canning very close to a bulkhead though, and I still have to question exactly what was going on, but you were there and I certainly was not.
In terms of your point about the flat hull form, it doesn't take much curvature at all to make the structure quite strong, or at least substantially more strong than if it were truly flat.
By the way, I don't think designers use flat underbodies to get more interior volume. They do that for performance and form stability. Indeed, flat bottoms actually decrease usable space below, as you have no bilges for storage, which means you need to get that storage elsewhere. Increasing beam forward gives you more volume, but I don't believe a deeper forefoot does that (though again, I could be wrong).
I totally agree, especially about the latter. I wrote the thread under yours while you were posting this!! Great minds, Dan!!