Michael Daly wrote:

On 16-Jun-2005, Peter wrote:


Your previous statement: "there is no correlation between overall length
and waterline length in kayaks"


From a perspective of useful information, that is still true.

No, it clearly was never true. Even taking the subset of kayaks you
chose, you calculated a correlation coefficient of 0.79 indicating a
very high level of correlation. If all kayak types were included the
correlation would be even higher.

You can argue
semantics all you want, but sea kayak lengths (LOA and/or LWL) are all over
the place.


made no such distinction that it only
applied to some set of kayaks that all had about the same length, nor
was it limited to sea kayaks.


But for the fact that the discussion is about sea kayaks. I guess you
just forgot.


Naturally the correlation coefficient will be less if you restrict the
kayaks under consideration to ones with fairly similar lengths (all but
one in the range from 16' to 19'). In a more complete list with play
boats, WW boats, surfskis, etc. also included the coefficient would be
much higher.


WW boats? You're joking, right? They have even more variation in LOA
vs LWL.

Not joking at all. In a compilation of all kayaks, the play boats and
WW boats will have short LOA and LWL figures, the surfskis will have
long LOA and LWL figures, and sea kayaks will come in in between. The
overall correlation coefficient between LOA and LWL will be very high.

I made no such restriction on lengths, I merely took the data that was
available and since we are discussing se kayaks, that's the data I used.

It still remains that overall length is not a useful indicator of
performance.

I have two sea kayaks. One has an overall length of 11' 8" and the
other has an overall length of 17' 6". I bet you can tell already which
one has a higher top speed - and you'd be right. Seems to be a pretty
useful indicator.

In the particular case of the two kayaks considered by the OP, their
lengths only differed by about 2' but the hull shapes appear to be quite
similar with no obvious difference in overhang. Therefore it's highly
likely that the Biscyne which is longer overall will also have a longer
waterline length.