"HK" wrote in message
m...
Frogwatch wrote:
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?

Hehehehe. You *are* quite the poster.

Yes, there are plenty of "variable deadrise" hulls around, but not because
of hinges.

If we are talking small monohull planing hulls, there are flat bottom
boats that pound at speed, boats with deadrise like yours that plane
nicely in a light chop, mod-vee hulls that do a bit better than yours in
more chop, and deep vee hulls. There also are hulls with rounded chines
that do a bit better than yours.

A hinged bottom? Hey...design and build one, and get back to us.



Active Variable deadrise. Actually an interesting concept. I know fighter
places have variable wing surfaces, etc. Maybe an inflatable sponson for a
tunnel on the sides, etc. At least it is a boating content thread. But
since you are imagination restricted, would be hard for you to accept this
as an interesting concept.