Fresh vs Saltwater weighting

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Dam0

Registered
Messages
34
Reaction score
6
Location
Lincoln, UK
# of dives
50 - 99
Recently passed my OW course in freshwater with a dry suit. In a few weeks ill be diving in salt water for the first time.

In freshwater used 8kgs of lead, when i take my first dip in saltwater should i start with 8kgs or up it slightly?

Ta

Sent from my Transformer TF101 using Tapatalk
 
If you weigh yourself and all your gear, and then multiply by 2.5%, you'll get the amount of extra lead you'll need for saltwater.


Sent from my iPad using Tapatalk HD
 
The proposed formula from fisheater is a general statement that does not account for variables like gender, body type, and etc. The short answer to your question is that you will need more weight in salt water. add 2 kilos to do your first weight check and adjust from there. You may need to add (or subtract) a little more. You will be more buyant in salt water than in fresh water.
DivemasterDennis
 
I don't mean to sound pedantic... but wasn't this explained clearly on your OW course?

Was what clearly explained? That salt water is more buoyant and fresh water [Yes] or how to calculate the lead difference between the two? [Not that I recall, hence the question. However I'm more than happy to reference my OW course material]

Dennis, thanks I'll try that.
 
The proposed formula from fisheater is a general statement that does not account for variables like gender, body type, and etc. The short answer to your question is that you will need more weight in salt water. add 2 kilos to do your first weight check and adjust from there. You may need to add (or subtract) a little more. You will be more buyant in salt water than in fresh water.
DivemasterDennis
I think fish eaters formula is a much more logical place to start than picking an arbitrary number. It does take into account variables. '

Speaking of body types I was helping a new diver on another forum. He weighed in at close to 400# without his gear. With he was close to 500#. Using fish eaters he started his weight check with an additional 14 pounds. He never would have noticed 4#.
Lets say OP weighs in at 180 and his gear comes in at another 50. 230 x .025 = 2.6 kilos. Close to your 2, but this is much more logical.
An obese person needs more ballast than a muscur one and this formula accounts for that. It's actually simple physics.
 
The proposed formula from fisheater is a general statement that does not account for variables like gender, body type, and etc.
Although two people of the same body weight (and gear) may/will require different lead based on body type (fat being less dense than muscle), body composition would not affect the formula for the lead differential for a given person (and gear) going between fresh and salt water.
 
Last edited:
Was what clearly explained? That salt water is more buoyant and fresh water [Yes] or how to calculate the lead difference between the two? [Not that I recall, hence the question. However I'm more than happy to reference my OW course material]

Dennis, thanks I'll try that.

Were you taught how to do a weight check?
 
In my O/W class the 'book' answer was 'about 7lbs' for estimating purposes. Obviously a neutral bouyancy test is required to get an exact answer.

The rest is.... :popcorn:
 
https://www.shearwater.com/products/swift/

Back
Top Bottom