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?

--
Matt Langenfeld
JEM Watercraft
http://jem.e-boat.net/

On Sun, 21 Mar 2004 15:24:16 GMT, Matt Langenfeld
wrote:

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.

That sounds a bit like a stripper I once dated, actually. G

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

Maybe both. I have a name for it, however:

"The Cuttlefish" or maybe

"Squiddy the Boat"

R

in article t, Matt
Langenfeld at wrote on 3/21/04 9:24 AM:

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?


Just because an idea is perceived as silly doesn't mean it's not innovative.
When designers at Chrysler first proposed that they build the mini-van,
marketing dismissed it. Their initial focus groups responded negatively
becasue the idea was presented as a vehicle that is NOT a car and is NOT a
truck. Well, who would want that?

You have a basic premise which seems reasonable. If you have the resources
to build a prototype, just do it! No one has to know if it doesn't work.

It would seem, at a glance, that the rear (I won't use the dreaded word)
could blend into the center portion over a longer area so that there isn't
quite so much plow effect.

There were a couple of perception boats that widened aft of the cockpit but
I think they were designed for surfing. I can't remember the model names.
Javelin maybe?

Build one!

PS. There's no H in wacky.

Peace

Hi

"Matt Langenfeld" skrev i en meddelelse
nk.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


That's a very interesting design , easy to produce a prototype for , the
reserve boyancy seem to have a function ,but can you stay onboard when it is
kicked around ?
P.C.

"Matt Langenfeld" wrote in message
nk.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.

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?

Because the enlarged ends are too low in the water in your design, the
boat would be slowed because the water would have to travel around them.
First out, then in, then out, then in. This would cause turbulance which
will slow the boat. If the increased volume ends rode higher on the hull
and were less exaggerated they would work better. If blended into the
hull shape they would look better. This would amount to a hull with
flaired ends at the gunnels and "tumblehome" amidships. This concept is
used possibly, though in a more subtle way, on a boat called a Baidarka,
invented a long time ago in the Aleutian Islands or Russia.
The fuller ends will also have the effect of making the boat ride over
the waves rather than going through them. Balancing the two movements is
a tradeoff either way. Do you want a corky buoyant hull that seesaws
over the water or a fast sleek hull that slices through the water?
Your hull would produce a boat that was extreme on the seesaw side.
Also, when your boat is leaned over to turn, the turbulance increases
and slows the boat alot.
I think your concept is interesting but that the features are too
exagerated to be practical. It also makes for a hull shape that is more
complex to build than ,say, a Greenland style Kayak.

Matt Langenfeld wrote:
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?

Matt Langenfeld wrote:
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?

What is the beam of the boat? If it's extemely narrow in the center, it
might work OK. If it's 20+ inches in the center and really wide at the
ends, you'll end up with a boat that pitches and pounds over waves and
will be hard to keep upright in beam seas, as it will be difficult to
lean and/or edge.

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.

I it one thing to guess by looking at the picture but a good way to try this
design out would be to make a 1/16 model and test it in a tank or even if
its possible the naval academy invented a program to test ship hull designs
and since then it has been made available to the public some manufacturers
use it to start their canoe designs off. Sorry I can't remember the name of
the program I know Swift canoe and Kayak uses it se if they mention it on
their site. Till it is physically tested and put through a simulation no
assumptions on wave friction or drag can be made you never know what works
out.

--
Abe Elias
Diving Sparrow Paddle Co,
http://home.cogeco.ca/~aelias
"Brian Nystrom" wrote in message
...


Matt Langenfeld wrote:
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?

What is the beam of the boat? If it's extemely narrow in the center, it
might work OK. If it's 20+ inches in the center and really wide at the
ends, you'll end up with a boat that pitches and pounds over waves and
will be hard to keep upright in beam seas, as it will be difficult to
lean and/or edge.