[Paddlewise] QCC boats and water line length ........

With the recent Maligiaq traffic I followed the links to the QCC web site (re
Maligiaq and the boat he will race) and was very interested in the articles by
John Winters on the site about his kayak designs.

http://www.qualitycomposites.com/speakboat.htm

The list comparing overall length vs water line length of many popular sea kayaks
at:

http://www.qualitycomposites.com/howlong.htm

makes interesting reading.

The general gist of the argument is that any part of the boat which overhangs the
water line length at bow and stern is a waste of materials, adds weight etc, and
does nothing for the boats handling or speed. John puts forward:

	"Some traditional designs have as much as two feet of skinny boat hanging out
over the ocean. It looks pretty but it doesn't do much"

John has designed some whizzy boats, and I'm aware that he also  knows a fair bit
more than I do about the design of traditional kayaks, but I would challenge that
the pointy bows of 'traditional' designs are functional as well as aesthetically
pleasing. It is very rare that I find myself paddling my sea kayak in anything
approaching flat water, and thus it is also very rare for the bow of my boat to be
just "hanging out over the ocean looking pretty". Paddling in any sort of sea the
whole of the bow is frequently immersed, infact paddling in whitecaps or a steep
oncoming sea so is pretty much the whole boat.  How relevant are the wave making
characteristics of the hull in flat water when the whole boat is being bumped
around by waves orders of magnitude larger? Has anyone thought about analysing the
shape of the deck, often frequently awash ?
Which has more windage a low flat deck with balanced raised bows and stern with
buyancy far forward, or a high angled deck with square bow and stern ? Which is
dryer ? Which is faster in sea conditions ?

I would also argue that flat water speed of a boat is a very poor measure of miles
you can paddle a day at sea, and optimising a boat for wave making resistance
doesn't necessarily make a good sea kayak. I demo'd a P&H spitzbergen at a
symposium in May (an example of a boat designed to be 'fast' with a high waterline
to overall length ratio). IMHO its a terrible boat and the last thing I'd want in
any sort of sea conditions. I was discussing my thoughts on this boat with a
friend recently who had had an aspirant BCU SSI turn up for his assessment in one.
For the assessment they were out in somewhat challenging condition's and the
result was the aspirant Senior Sea Instructor (aspirant but to be on the
assessment never the less an experienced paddler - I'm not too hot on BCU stuff,
but I believe you call SSI's level 4 coach in the states?) couldn't come close to
keeping up in the conditions with his 'racing' boat. The assessors having a ball
surfng along in supposedly much slower boats were apparently mightily amused. I'm
aware that design of the bow profile isn't the only feature of this boat, but my
point is that in real conditions design measures like the water line length and
computer predicted drag do not equate with miles you can cover at sea. In open
water conditions the ability to surf following seas  (you can therefore also ditch
your rudders <grin>) keep the paddler reasonably dry, and  balance and cope with
wind are key factors which the traditional pointy bow with low decks achieves.
They have the added benefit that the shape will ride up over objects in their
path - apparently important for the traditional hunter landing and launching from
ice floes, but more importantly for the paddler today essential for a number of
rescues. Maybe of minor concern  but there is also a useful safety bonus of raised
bows in collisions. I watched a potentially nasty coming together between a
knordkapp and a sirrius last week in surf. Experienced Paddler in the sirrius was
confronted by an inexperienced surfer in a knordkapp surfing very rapidly offline
towards him. He capsized his sirrius, and you can bet he was glad the knorddapps
bows were the shape they were as it rode up and over his hull. He rolled up with
no damage to either boat or persons - due in great part to the bow shape of the
knordkapp.

For *** FLAT *** water use, I think that John's arguments about waterline length
make a lot of sense. The QCC boats look not dissimilar in bow and stern shape to
an old flat water touring boat I have sitting in my yard, which at 15 or so feet
long with a water line length of 15 or so feet, is indeed noticeably quicker on
flat water than my sea kayak, with an overall length a couple of feet longer. But
I wouldn't want to paddle it in any sort of sea state.


Cheers

Colin Calder
57º19'N  2º10'W

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