Who has had their boat in boat salt and fresh water and noticed a difference is speeds.
And can you attest that it was not due to altitude differences?

salt is slightly faster due to buoyancy with all other conditions being identical....

I bought a 330 Sundancer several years ago that was a salt water boat. On an inland river (90 miles inland/ freshwater) the boat sat almost 2 inches lower in the water. Don't know speeds, but it has to make a difference.

not a big deal with under 70 boat anyways.

2 mph on my rig

I saw no real difference in Salt vs. Fresh. Salt is more bouyant but it is also denser. One of the magazines hashed this out a couple years ago. Temperature, humidity and altitude seemed to be much bigger factors.

Offshore vs. Onshore

2-3Mph at least

Mine was a tad faster in salt, but I could definately feel the more bouancy of the SW in the handling of both of my boats.

That was Poker Runs America and they did a real in-depth analysis on the subject...they concluded that there was little difference. And yes, they confirmed that temp and humidity were much bigger factors.

I've found temp , humidity , and altitude make more difference than salt/fresh which seems to be little to nothing in mine.