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?

steveJ ) writes:
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.

another way of lookign at this is in a "normal" boat the paddler has to
work to push the water aside at the bow and again to overcome the suction
as the water comes togehter again at the stern. In a wasp-waisted
waterline the water is pushed aside twice and the suction overcome twice
so its extra work.

again, the paddler has to work to overcome the friction between the hull
and the water. On a wasp-waisted boat there would be more surface area in
contact with the water, hence more surface friction, and the paddler has
to work harder to move the boat through the water.

there are wierd boats that are harder to move though the water but they
satisfy some other imporant requirement. a white water kayak comes to
mind. these boats depend on water current to move them along. they
sacrifice speed and ease of paddling for maoeuverability. such boats are
special purpose. if you have a special situation where the wasp-waisted
boat would be better than a normal boat which paddles easier go for it.

I wasn't actually able to look at the boat because the computer at the public
library was denied access to the Developement web page for some reason.

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I know ...why not design it so your hull extensions are OUT of the water
until the paddler tips 10 degrees or so?

Brian


"William R. Watt" wrote in message
...
steveJ ) writes:
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.

another way of lookign at this is in a "normal" boat the paddler has to
work to push the water aside at the bow and again to overcome the suction
as the water comes togehter again at the stern. In a wasp-waisted
waterline the water is pushed aside twice and the suction overcome twice
so its extra work.

again, the paddler has to work to overcome the friction between the hull
and the water. On a wasp-waisted boat there would be more surface area in
contact with the water, hence more surface friction, and the paddler has
to work harder to move the boat through the water.

there are wierd boats that are harder to move though the water but they
satisfy some other imporant requirement. a white water kayak comes to
mind. these boats depend on water current to move them along. they
sacrifice speed and ease of paddling for maoeuverability. such boats are
special purpose. if you have a special situation where the wasp-waisted
boat would be better than a normal boat which paddles easier go for it.

I wasn't actually able to look at the boat because the computer at the
public
library was denied access to the Developement web page for some reason.

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You might have something there.

This wasn't intended to be a speed racer. Just a WACKY ....lol.....idea
about something stable for fishing but without having to reach way over
the sides to paddle.

If I did get into a serious design, I'd smooth out the transitions to
minimze turbulence.

I even know the name for it..."The Bone" because of the shape.


Brian D wrote:
I know ...why not design it so your hull extensions are OUT of the water
until the paddler tips 10 degrees or so?

Hi

"Matt Langenfeld" skrev i en meddelelse
ink.net...

If I did get into a serious design, I'd smooth out the transitions to
minimze turbulence.

And why that ------ turbulence is acturly just what can eliminate drag ,
make the wet surface act different , but ofcaurse you need the feel about
how a hull act or rather the spots where it is a good idear to with
turbulence.
The boyancy can also come in handy, as you se with north sea vessels -----
just emagine one of these without the huge stern, it would not climb the
waves but go strait into it , beside that far from the middle of the boat
the extra volume will proberly make the hull more smooth moving.
Realy the art about making a good fast design, is to have the feel about how
turbulence could effect maby two thirds of the hull , making less drag than
what you would expect as an amature builder.
Anyway you will not know before you made atleast a scale model, making such
one, would be very easy if you just had the framework to place the panels.
-------------- Now Im'e not talking about 50 Kilo of clamps just to hold
temp. frames , but an assembly framework that would support itself while
showing the exact form, --------- like what you se here ;

http://groups.yahoo.com/group/Cyber-Boat/

P.C.

"P.C." ) writes:

And why that ------ turbulence is acturly just what can eliminate drag ,
make the wet surface act different , but ofcaurse you need the feel about
how a hull act or rather the spots where it is a good idear to with
turbulence.

a kayak with a bulb under the bow, now there's a wacky thought



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Hi

"William R. Watt" skrev i en meddelelse
...
"P.C." ) writes:

And why that ------ turbulence is acturly just what can eliminate drag ,
make the wet surface act different , but ofcaurse you need the feel
about
how a hull act or rather the spots where it is a good idear to with
turbulence.

a kayak with a bulb under the bow, now there's a wacky thought


Well if you ever looked down at the water near the hull, with just a row
boat, you be surprised that some of the water stay in the same place even
the boat move with good speed ; --------- it's like some places on the hull
surface ,the same water circulate slowly , leaving the "wet surface" being
one inbetween two different turbulent small currents.
Or looking behind a boat while moving, you also se the same water and
bobbles staying the same distance from the end of the boat, even other water
just inches away ,just rush past. --------- Also formig cirtain parts of the
hull, can make the water rush as out a tunnel from parts of the hull, where
the drag will vaccum other water in slower but in bigger quantities ; only
thing that will show is a model.

P.C.


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