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Kayak and Canoe Design Bulletin Board
Re: Wide sterns
Posted By: Greg Jones In Response To: Re: Wide sterns *Pic* (Nick Schade - Guillemot Kayaks)
Date: Tuesday, 18 June 2002, at 3:30 p.m.
: I had been thinking about this kind of shape for a while. I ended up building
: the Aleutesque because what I had drawn up looked so cool I figured it
: would be worth it even if the performance was not great.: But I did have a theory going into it. A "transom" stern may have
: the effect of making the boat appear longer in the water than it actually
: is. At speed the water just sheets of the end (like it is planing) and
: leaves a depression in the water that acts like part of the hull as far as
: the wave making is concerned. I don't know if this really works, but it is
: the theory.: This also lets me keep the width of the boat farther aft which like Hans
: suggested improves the stability in an otherwise narrow boat.: I do think that on a big wave the full stern section should help support the
: boat to the point that it may actually plane. However, it is possible that
: there is so much lift in the stern that it keeps the boat quite flat,
: which may force the bow down into the water ahead of the wave. This would
: be particularly true on short wavelength surf. The result may be that the
: boat has a tendancy to perl or broach.: I need to try the boat in something other than flat water to get a better
: feel for the answers to some of these questions.Nick,
Congratulations on another beautiful design!
Your comments on the transom stern possibly making the boat “appear” longer is an interesting comment I’ve heard mentioned before both by baidarka builders and yacht designers.As you probably know, an extreme case of this idea was used unsuccessfully by the America’s cup Yacht Mariner in 1974. There’s a short and interesting note describing the design here: http://homepage.mac.com/pegis1/pages/tools.html (Scroll down to see the commentary).
I’m not sure I believe the longer length argument but honestly don’t know.
Wouldn’t it be fascinating to get your design into a towing tank and take some measurements… Please post an update periodically and keep us abreast of your testing.Thanks very much for sharing your work with us – a beautiful boat that challenges the mind. Who could ask for more?
Cheers,
- Greg
http://homepage.mac.com/pegis1/pages/tools.html
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