fresh water to salt water weight formula ... conversion charts

[Granny Scuba]

Are there any formulas for weighting? Conversion charts ???

Say a 5"10 200 lb person with a 5mil takes 14lbs in fresh water so they would take _________ in salt water?


If you are in salt water with only a 1/2 mil skin would you take more than being a fresh water with a 5 mil?

Thanks

 

[AZFlyingDiver]

There are basic weight guidelines in PADI's Peak Performance Buoyancy program, but as with any such guide, it's no substitute for a good buoyancy check.

That said, the answers to your questions are:

1. a 200 lb diver using 14 lbs in fresh water would use 21 pounds in salt water
2. there's not a pat answer for going from a skin in salt to a 5mm in fresh because the gear configuration, like whether you're also considering the hood/gloves/booties, etc., has an effect.

Again, there's no substitute for a good buoyancy check whenever you're diving a new environment or gear configuration or haven't dived in a while.

 

[AZFlyingDiver]

And note, that the answer I gave for #1 assumes all other gear is the same...

Happy diving!

 

[DiveNav]

You can "assume" that the density of salt water is ~1.03 times bigger than the density of fresh water (at the same temperature).

So, if you are using EXACTLY the same gear configuration, in salt water you will 1.03 times more weight than in fresh water

Alberto (aka eDiver)

 

[vladimir]

You can "assume" that the density of salt water is ~1.03 times bigger than the density of fresh water (at the same temperature).

So, if you are using EXACTLY the same gear configuration, in salt water you will 1.03 times more weight than in fresh water

Alberto (aka eDiver)

Yes.

Just to be clear, DiveNav is talking about your total weight, not the weight you carry for ballast. So if you are neutrally buoyant in freshwater and tip the scales at 300 pounds fully geared up, add ballast to make that 309 pounds and you'll be neutral in saltwater. (I'd go with 1.025 as a better estimate of average ocean specific density--it varies--but that's really quibbling.)