salt vs. fresh water buoyancy, feel

[Sailboarder]

There is a link above that explains than humid air is less dense than dry air...

Also, what you are describing are ground effect vehicules. They work because the airflow around the wings is confined by the water or the ground and provide more lift and less drag than in usual flight further from ground. You can look it up on wiki. So it's not because air is denser but because air provides more lift since it cannot move down as it would normally do when the wing goes through.

[isobars]

Yup. The trapped air cannot just move away, so it "fights back" via compression. I watched a heron fly off into the sunset last night, his wingtips just inches off the water with each downstroke. Ditto the hundreds of ducks who scramble out of our way as we launch. And ditto mountain rescue helicopters, who use the ground effect to increase their operational ceiling and/or hover just off the surface at high altitudes. The Mount Hood helo crash of 2002 is a graphic example.

[spennie]

What you guys are saying makes more sense than the video I saw, I'm going with your explanation. I'm sticking to my smaller fin statement, however, since that is based on my experience. Buoyancy is also higher in the ocean, but not sure by how much. I work at a college, maybe I can find out for sure.

[isobars]

Read Windward1's first post in this thread.

[spennie]

That's weight, not buoyancy. I'll check with the Physics Dept. next week.

[isobars]

Weight (i.e. mass, at sea level) divided by volume ∝ [is proportional to] density ∝ buoyancy. If the weight per cu ft differs by 2.56%, so does the buoyancy.