OK, I keep telling myslf that someday I'm gonna figger out hull speed
so I ust read a buncha stuff bout it, still makes no sense to me. So
the bow and stern waves merge at hull speed, why cant they just merge
and go past each otther? It'd be the sum of two waves (I s'pose they
arent pure sine waves but something like a damped sine wave).
Does hull speed work the same way for submarines? Could I add
extensions to my sailbaot to increase its hull speed? Maybe
lightweight inflatable extensions?
My gut reaction is there is something wrong with this whole (hull)
idea of whole speed.

On Tue, 15 Jan 2008 18:07:35 -0800 (PST),
wrote:

OK, I keep telling myslf that someday I'm gonna figger out hull speed
so I ust read a buncha stuff bout it, still makes no sense to me. So
the bow and stern waves merge at hull speed, why cant they just merge
and go past each otther?

They don't merge, at least not in the way that I think of merging. As
speed increases, the height of the bow and stern wave increase, and
the boat basically becomes trapped between them. The formula for
theoretical hull speed computes the velocity of water waves for a
given wave length, and assumes that a boat of that length can not
easily be made to go faster. There are exceptions of course for
different types of hulls, but for average displacement boats the
equation works reasonably well.