"Bryan" wrote in message
. com...

"Calif Bill" wrote in message
ink.net...
Not for dialup.

http://www.youtube.com/w/Extreme-Spr...rint%20jetboat

Some other neat videos also.


Bill,
Is it an illusion or are those boats turning as sharply and moving as fast
as the video suggests?

No illusion, the real deal.


If so, what's the design feature that makes them able to make such sharp
controlled tight turns at speed?
Two things. First, jet propulsion allows for near instant changing of the
vector of thrust. When you turn the wheel on a jet, all you are moving is
the small short nozzle at the end of the jet drive. Since the nozzle has
very little mass, and is more on the surface of the water rather than
underneath it, there is very little resistance to movement, and it is a very
short throw, lock to lock. Second, notice that all these race boats have a
very flat bottom and very little keel. This allows the stern to be kicked
out to the side nearly immediately, thus changing the heading of the boat
nearly instantly. If you've never driven a jet boat, or ridden in one that
is being driven by someone that isn't afraid to demo the unique
characteristics of a jet, you're really missing something. Big fun.