Skipper wrote:


I've experienced a consistent 2 MPH delta with a planning hull at WOT
from fresh to salt. That translates into a 6% difference. Even though
that's been my observation, it just doesn't seem right. I'm also curious
about the East/West Coast speed delta. Suspect there is one. Bet there
is also a corresponding fuel penalty for displacement hulls due to this
effect. Perhaps one of the boating rags will publish some data on this
in the future. Would seem the mix of fresh and salt you have in your
area would have had someone looking into this...

--
Skipper

The challenge with a real-life comparison is that it would never be
possible to change only the salinity and temperature of the water.
Differences in wind and current would dwarf any tiny difference between
fresh and salt buoyancy. There's no way to duplicate wind
and current, exactly, in any two locations even pretty nearby in Puget
Sound....and there will alway be more or less wind, and typically less
current, inside the locks in the fresh water. The best test for this
difference would probably be conducted in a test tank at one of the
boat factories, but I doubt they have any provision for filling their
tanks with sal****er.