salt vs. fresh water buoyancy, feel

[J64TWB]

Just wondering. If I like a board at 111 liters tested in salt water, but want to use it in fresh, should I go up to the next size?

[LeeD]

Yes, to 113 liters.

[adywind]

Less buoyancy definitely, I can feel it when swimming. Add to that the typically gustier inland winds and you can bump up a size with confidence. Someone was actually recommending it in an article I once read.

[windward1]

Saltwater weighs 64 # per cubic foot.
Freshwater weighs 62.4 # per cubic foot.
So only a 2.56% difference. Not all that much. LeeD is correct.

[J64TWB]

So the math says 2.5. Not much. How about when planing over denser water? Is there some amplified perception of float? Kind of like a wind chill.

[bred2shred]

Yes, but don't forget to also consider that on humid days, the air will be more dense, so you need to reduce your sail size accordingly. Oh, but if it's hot out your rig will heat up and expand making it larger than when it's cold so you need to factor that in too. And if you're sailing on a lake at an elevation above sea level, then the gravitational force on your gear and body will be reduced, so that also needs to be considered.

...or you could just sail it....

sm

[pete1111]

Sorry but dry air is more dense

[Sailboarder]

First, I guess that while planing, the difference will be marginal.

However, off the plane can be different in some specific circumstances. I sail Kona and I'm about 210 lbs. I sailed a Kona board on salt water for the first time this February. It happened several times that I was sure to go overboard but it didn't happen. Since I skied more that usual that winter, I was convinced it was because I had better balance. But I had a reality check several weeks later when I sailed back on fresh water.

A craft stability has a tipping point. By being heavier, I'm closer to that point. A change of water density (and surely a change in my weight) makes a noticeable difference.

Enough to change board size? No for sure! But I've read elsewhere (maybe here too...) people being ridiculed for saying they feel a difference, and I now side with them.

[windward1]

Most folk can taste the difference.

[swchandler]

I think that the difference is really negligible, particularly when sailing about. I would say the same if you are wearing a wetsuit, because a wetsuit provides notable flotation while in the water. However, without a wetsuit you might begin to notice some difference, especially if you're less than a confident swimmer.