It seems that deadrise has a radical effect on the ability of a boat
to get on plane quickly and thus use less fuel. More deadrise makes a
boat punch through waves better but increases draft and reduces fuel
economy in smaller seas. I assume that variable deadrise has been
tried. Of course there are boats that try to use hull shape to
accomodate varying conditions but not too successfully.
My Tolman has about 10 degree deadrise and is very light so is very
fuel efficient but pounds a lot in chop so I have to slow down to
about 12 kts. Why not some mechanism that would consist of another
outer variable hull layer that would be hinged at the chines allowing
the keel portion to move downward to increase deadrise. It would have
a flexible stiff plastic piece at the front to keep water out of the
area between the two hulls. Is this simply too complex for too little
benefit?