"Michael Daly" ) writes:
On 28-Aug-2003, (William R. Watt) wrote:

there's *nothing* I haven't tried in 6 foot or higher waves. what millponds
do you paddle in? 6 foot waves are for children. we get wakes on the canal
higher than that.

Still bull****ting, huh willy?

what it says in the subject line

Not to mention the wonderful bucket seat in the Ellesmere.


a small concession to comfort. I did like the lower back support on some of
the kayaks I tried. few had any above the hips.

Long, narrow hulls don't roll in waves the way wide stable kayaks do. That's
why deployed sponsons are a bad idea in rough conditions. Not rolling means
more stability in rough conditions.

hull stability comes from both length and beam. a long fast boat can be
just as stable as a short beamy boat. older sailboats were long and narrow
but heavy. moderns sailboats are light and beamy. the apddling and sailing
boat I built with the sponsons on it is both narrow and short. no sponons,
no renetry.


Round bottom hulls have _no_ initial stability. If the shape doesn't change with
angle of heel, there is no position that is more stable. This makes for a very
tippy kayak = not safe.

round bottom boats with sponsons above the waterline have both superior
wave riding and plenty of reserve bouyancy. If you visit my website but
leave off the "/top.htm" you get an indexed list of all the files some of
which are in any HTML references. Scroll down to files bluecanuxx.yyy to
see text and photos describing a boat I made by sawing completely round 55
gal blue plastic barrels in half and mounting sponsons on the gunwales and
read about the stability tests.


Hard chined kayaks typically have excellent secondary stability and are rock
solid in the roughest conditions. That is what the eastern Canadian and
Greenland Inuit used and they could have made their kayaks any way they wanted.

you've fallen into the "traditional" trap. there's no indication they even
imagined round bottom boats. let alone tried and descarded them. with
little in the way of framing material to work with it was materials which
shaped the boat as is the case with all native craft. I wasn't there
either but I still have the better argument.

Waves catch on chines before they catch on sponsons but how much
difference that makes to very light displacement hulls like kayak I don't
know. However, in longer kayaks the chines are also longer and more
subject to wave action.

Waves break when the length is 7 times the height. If the wave crests
match the length of a 20 ft kayak they'll break at 3 ft approx. If the
wave is cresting at one end of a 20 ft kayak and the wave trough is at the
other end that's a 40 foot wave and it will break at 6 ft in height
approx. In either case you should have got off the water before then.

The worst boating situation is waves coming from more than one direction.
You can fall right into a hole in the water. It has happened to me
somewhat artificially in the 7.5 ft boat I have the sponsons on, caught
between 2 ft powerboat wakes on a canal. The sides on the boat are 1 ft
with a 4" draft leaving 9" of freeboard. The beam is 24" like a kayak
(length 7.5 ft as mentioned). Boat didn't ship a drop. The boat sails in
quite stong winds for its size in smaller waves. The key is to lower body
weight (centre of gravity) which a kayak paddler cannot do sitting upright
in a tiny cockpit. I can't see a kayak paddler riding out a storm sitting
bolt upright in a narrow boat without sponsons unless he or she is really
into rolling which I imagine would be exhausing. Better, I think to have a
large cockpit you can lie down in. There have been kayaks, although
homemade by boat desingers and not mass produced, in which one could
recline, even sleep in overnight as Herreshoff did on his.


V-bottoms track well with less weathercocking than round bottoms and are decently
stable if the V is not to sharp. That means less fatigue and hence, more safety.

fatigue = safety in boat design? that's a new argument. you rest
when you get tired. that's safety no matter what boat you're in. I'm not
sure about the V-bottom speed argument as round bottoms have least wetted
surface per pound of displacement. That's just theory and I haven't any
tank tests or computer simulations to support it.

Stop trying to argue with kayakers about kayaks when you don't know anything
about them.

Stop trying to portray necessarily limited and subjective personal
impression as fact. You seem to be arguing from a sea kayaking perspective
using production boats (which are marketed on appearance as much as
anything else).

What's your experince with sponsons? I've used them with good results on
two boats I've desinged and built for myself.

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