shouldn't optimized designs be "salt" OR "fresh" water?

[Squidly-Diddly]

shouldn't optimized designs be "salt" OR "fresh" water due the substantial differences in density? It seem quite noticeable in a kayak or rowing scull.

Do nautical CAD programs make calculations for both, and what tends to happen when the numbers get re-crunched?

In related news, I don't see a lot of 'air' in those sails on Peru's Lake Titicaca at 12,500 ft.

[messabout]

There is a density differetial but it is not a big one, only two and one half percent. I am pretty sure that the skippers of big vessels like tankers or bulkers take account of the difference. A ship entering the St. Lawrence seaway from the east would begin to draw more water as they progressed toward some great lakes destination. A dinghy or other small boat would not notice much difference I suspect.

I take your remarks about kayaks in fresh versus salt water as a point of interest. A kayak that displaced...say 240 pounds would have a tiny bit more wetted surface in fresh water than in salt. The difference would be insignifigant at 165 cubic inches of displaced volume. Most kayaks would have a surface difference of about one half square foot of surface. The boat would feel a difference of 6 pounds of weight more or less. An expert paddler would feel the difference. Klutz paddlers, like me, probably would not

[DMacPherson]

See article on page 2, "Performance differences in fresh and salt water":

http://www.hydrocompinc.com/knowledg...ge/tex0502.pdf

Regards,

Don MacPherson
HydroComp, Inc.

[rwatson]

Originally Posted by DMacPherson

See article on page 2, "Performance differences in fresh and salt water":

http://www.hydrocompinc.com/knowledg...ge/tex0502.pdf

Hmm, no. That was a link to "Effects of SHALLOW water", not FRESH/SALT.

Have you got another link?

[DMacPherson]

See page 2 of the PDF.

Don MacPherson