Salt VS fresh

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A. Boyette

Registered
Messages
17
Reaction score
11
Location
On the water
# of dives
200 - 499
If I use 19 lbs of weight in salt water how much will I use in fresh water?
(all other factors being the same)

I'd like to try to get my weight in the ball park so I don't have to fool around with weights too long tomorrow at the lake.

TIA
 
I'm sure I will get over rode by a scientific answer but I use 20 salt and 12/14 fresh
 
Subtract 2-2.5% of your total weight, equipment, suit, you from your saltwater lead and it will get you close so long as you are using the same equipment. If you are changing equipment all bets are off.
 
If I use 19 lbs of weight in salt water how much will I use in fresh water?
(all other factors being the same)

I'd like to try to get my weight in the ball park so I don't have to fool around with weights too long tomorrow at the lake.

TIA
Probably around 14.
Better answer: take off an amount of lead that is 3% of your body weight.
Best answer: do a weight check at the beginning of the dive, and add 5 lbs to compensate for the weight of the air to be used up.
Very best answer: do your weight check at the end of your dive when you are fully wet, your air is down to 500 psi, and you are relaxed.
 
I don't know what type of lake diving you are doing, but 4 to 5 pounds less should get you in the ball park.

Since you are lake diving, if you are required to have a dive flag, I usually toss a few weights either in the dive flag float or set it close to whatever I tie the flag off to. Take weight off or add weight as needed until you are dialed in.

If you are using the same entry and exit point, it's easy to have weight around, or leave weight if you feel like an anchor. I've never had any grow fins and swim off either, despite diving some crowded parks.

Good luck, dive safe,
Jay
 
So your saying he needs to take off .475 of a pound?
Total weight. I weigh about 340# as I get into cold saltwater. Subtracting about 7 lb gets me changed over to fresh water. At neutral buoyancy you displace your total weight in water. That is why you don't rise or drop. Your total weight, equipment, lead, body, air in your tank, everything attached to you weighs the same as the water you are displacing at neutral buoyancy. Saltwater weighs 2-2.5% more than fresh water so with the same equipment, displacing the same volume of water but diving in fresh water instead of salt water you need to drop 2-2.5% of your total weight and you do that by dropping the amount of lead that you carry.
 
13 or 14.
 
It is roughly a 20% difference between fresh and salt water. Assuming you aren't changing anything else, I would drop from 19 lbs. to 16 lbs.
 
https://www.shearwater.com/products/perdix-ai/

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