Message-Id: <199711201359.IAA46218@onlink4.onlink.net>
From: "John Winters" <jwinters@onlink.net>
To: <baidarka@lists.intelenet.net>
Subject: Re: Skin Boat and Hard-shell
Date: Thu, 20 Nov 1997 07:52:52 -0500
Robbie wrote;
> Perhaps, and this is merely by way of discussion, one is asking the
> wrong question with repect to the performance of the vessels in
> question. This Speed Boss sounds like a great toy. Just several
> questions
>
> 1) Does it measure vertical acceleration as well horizontal ?
No, just velocity through the water and maximum and minimum speeds with
each stroke.
> 2) Are you measuring directly (or indirectly) the human effort or power
> required to drive the vessel
No measure of human effort.
> 3) Are you able to quantify windspeed (absolute, apparent), wave height,
> water depth and wave length, water temperature etc.... ?
No.
> 4) Displacement (as tested) of the kayak
All test are done with constant displacement.
>
> If the answer to these questions is yes then it MAY be possible to use a
> package such as SAS to (legitimately) compare performance of the vessels
> using one of several procedures (I'm not a statistician so I couldn't
> say which would be the best tests or data modeling processes to use).
Regrettably the answer to too many of the questions is "no".
>
> My guess is, getting back to my introductory (and somewhat flipant
> remark), that it would better to test the nul hypothesis that the
> performance of a kayak is not affected by the paddlers technique.
> Because only then can one be sure that the difference in performace
> BETWEEN craft is the sole result of the craft themselves - otherwise for
> each test BETWEEN craft one has to model the behaviour of the paddler.
I think this is the problem when using paddlers. Some work their buns off
and get no where (figuratively speaking) Some seem to loaf along and make
great progress. Some, like me. can't seem to get it consistent.
> THE ALTERNATIVE IS TO REPLACE THE PADDLER WITH AN ELLECTRIC MOTOR WHICH,
> FRANKLY, DEFEATS THE WHOLE POINT OF BUILDING KAYAKS FOR PEOPLE IN THE
> FIRST PLACE.
Absolutely! If only I weren't so curious about why. :-)
Cheers
John Winters
Redwing Designs
Specialists in Human Powered Watercraft
http://www.onlink.net/~jwinters