On Sep 21, 1:59 pm, Davej wrote:
Some time ago I was told by Vaclav Stejskal of OneOceanKayaks.com that
beyond 17 feet or so longer boats do not provide an efficiency
advantage. Yet we know that surf skis and other racing boats are often
as long as 22ft. After playing with Kayak Foundry, a freeware program
by Ross Leidy (http://www.blueheronkayaks.com/kayak/index.html) I am
seeing the same sort of results that Vaclav Stejskal predicted. Adding
length is not improving the total calculated drag. So what is the
truth of the matter? Is the standard method of calculating drag from a
computer model inaccurate?

http://www.westsideboatshop.com/http.../surfskis.html

Take a look at an Epic Endurance
http://www.seakayakermag.com/PDFs/Endurance_stats.pdf

Look at the amount of waterline and wetted surface.