Weights in Salt VS Fresh Water

[don98]

So far, my diving experience has been all fresh water.

Since you are more positivly bouyant in salt water over fresh water, I assume you will need to add additional weight. Is there a rule of thumb on how much more?

 

[simbrooks]

Add about 5-6#

 

[Stirling]

So far, my diving experience has been all fresh water.

Since you are more positivly bouyant in salt water over fresh water, I assume you will need to add additional weight. Is there a rule of thumb on how much more?

The rule of thumb is to account for the difference in specific gravity of salt water and fresh water.

If you are diving the *same* equipment (wet suit, BC, tank, etc. all identical), take the TOTAL weight on land of EVERYTHING that you are wearing into the water, INCLUDING yourself and your wetsuit and other gear and the weights that you now use in fresh water. Multiply that total weight by 1.025 to go from fresh to salt water.

If it all adds up to 240 pounds, for example, 240 x 1.025 = 246. You need to add 6 pounds to achieve the same result in salt water that you are now getting in fresh water. If it all added up to 200 pounds now, the result would be 205 and 5 pounds of additional weight. Every 40 pounds of total weight requires one additional pound of weight to go from fresh to salt water (and one less going the other way), so for most people the difference is probably going to be somewhere in that range of 5-6 pounds. If your total is closer to 280, you might need 7 pounds, and a smaller or less encumbered person might need only 4.

 

[O2BBubbleFree]

So far, my diving experience has been all fresh water.

Since you are more positivly bouyant in salt water over fresh water, I assume you will need to add additional weight. Is there a rule of thumb on how much more?

For starts, you can try this:

http://www.scubaboard.com/showpost.php?p=649132&postcount=3

Then, of course, fine tune it with your buoyancy check.

 

[knotical]

Multiply that total weight by 1.025 to go from fresh to salt water.

Slight variation: You might want to use 3% instead of 2.5% since the specific gravity of seawater can go as high as 1.03 near shore (where most of us dive), or to add a bit of cushion. You can always shed a pound or two later.

 

[don98]

Thanks for the info. Exactly what I was looking for....

 

[ChrisA]

So far, my diving experience has been all fresh water.

Since you are more positivly bouyant in salt water over fresh water, I assume you will need to add additional weight. Is there a rule of thumb on how much more?

Will you be wearing the same exposure suit salt water? If moving from a cold lake to tropical salt water you would loose weight.

 

[don98]

I will be wearing the same suit. I've been diving in fresh water springs in Florida - so the water is pretty comfortable all year.

Will you be wearing the same exposure suit salt water? If moving from a cold lake to tropical salt water you would loose weight.

 

[mm777]

For starts, you can try this:

http://www.scubaboard.com/showpost....132&postcount=3
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That was helpful. I'm kind of in-between on the chart though. If I weigh 155 and have a shorty with long sleeves should I think about starting with 17 lbs in salt water ? thanks

 

[Tom725]

I will be wearing the same suit. I've been diving in fresh water springs in Florida - so the water is pretty comfortable all year.

If my memory serves me, the fresh water springs are near 70 degree. The ocean can be over 80. You will likely want less exposuer protection in the ocean.