On Sun, 21 Mar 2004 18:16:24 GMT, "Fred Klingener"
vaguely proposed a theory
.......and in reply I say!:
remove ns from my header address to reply via email

Basically you have taken the central part out of the fat bits on some
of the sit-on-tops...ummm...scupper Pro IIRC.

Problems? Depends on the use.

(1) Turbulence around the sudden change at each end would slow the
boat, even with the horizontal "diamond" taper shown. Needs to be run
gradually into the boat to the paddle point.

(2) If turning sharply, the boat could be a bit sluggish. The ends
need to be slim.

(3) While the boat would lift well to a wave, it would also be very
rocky, and pound.

(4) roll-righting could be tough.

As was said, build one or modify an old boat that you know to be
tippy....then let me know. I have wondering about this sort of idea
for years.

"Matt Langenfeld" wrote in message
ink.net...
A friend and I were goofing around talking about hull shape and we came
up with this:

http://www.jem.e-boat.net/images/Development/XYak1.jpg

The idea was stability and reserve buoyancy but still having the ability
for nice tight vertical strokes.

I'm not sure what to think. Innovative or just plain silly?

Innovative? Yeah, but not completely. Some downriver canoes have the
pronounced concavity where the paddle shaft goes and some have pronounced
flairs aft to recover some of the roll stability. Their radical shapes are,
I think, dictated more by rule-skirting than hydrodynamics.

Silly? Most 'new' designs look just plain silly to me.

Functionally, I think you'd see two significant effects.

First, pushing the bouyancy out to the ends will tend to make the boat
pitchy. You might need foam forehead and nose pads on the foredeck. It
wouldn't be a waterfall boat.

Second, if you visualize the fore-and-aft displacement map, you'll see a
pattern that looks like a hogged hull (negative rocker), and this will
surely have an effect of the boat's yaw response. How much? I dunno.

I like the advice another poster offered. Build one. You don't have to say
a word if it doesn't work.

Cheers,
Fred Klingener

PS No 'h' in wacky? That's whack, man.

************************************************** ** sorry

..........no I'm not!
remove ns from my header address to reply via email

Does Bill Gates dream of electronic sheep?

Old Nick wrote:

(2) If turning sharply, the boat could be a bit sluggish. The ends
need to be slim.

That's a very good point. Edging the boat would not lift the ends clear
of the water. Rather, they would dig in, probably making the boat harder
to turn than if it was on an even keel. They would also add drag
whenever the boat is edged or leaned or the water is uneven.