On Mon, 25 Apr 2005 20:16:09 GMT, Albert P. Belle Isle
wrote:


Our resting WL is 24'. To maintain a 1.34 constant and get the speeds
we've verified while definitely not surfing, our effective waterline
would have to be greater than 35'. That's a LONG way behind our transom!


Jere -

As a quick calculation, 24ft DWL would yield a hull speed of about
6.6kt with a speed-length coefficient of 1.34. To get to 7kt, the
effective DWL at 1.34 would be a little over 27ft - not 35ft.

My previous boat had a DWL of 28ft, for which a speed-length
coefficient of 1.34 would predict 7.1kt.

I easily got 7.4kt on beam reaches, which would say my real
coefficient was almost 1.4 (or that my effective DWL at 1.34 was a
little over 30ft - a two foot "push-back" of the sten wave, which was
roughly how the peak of the stern wave looked from my cockpit.

Regards,
Al