Trim in Fresh versus Salt water

[jagfish]

Let's say a hypothetical diver needs about 4kg total weight (including SS backplate) in salt water with his exposure protection.

If we take this same diver into the pool for trim work with the same gear and weight as ocean (yes we'd be overweight in the pool), we have about 1 kg to play with if we assume the backplate and hardware is 3 kg.

If we find a sweet spot for the weight placement to result in good trim for this diver in the pool, can we expect the trim balance in the ocean to remain as it was in the pool, or would the effect of SW buoyancy on different parts of the body possibly cause the need to redistribute our 1 kg of "trimable" weight?

I don't do much pool work, so I've been wondering ---

 

[mania]

Well
I understand it this way. In every new conditions you should do the check dive to check needed weights. There are different for different waters. Even the salty one is not the same (different conditiond in the Dead or Red Sea and different in the Baltic Sea).
So - the old procedure - almost empty tank, 3 meters, and adding or loosing weights.

Once this is done the trim should be OK.
Mania

 

[m3830431]

I would say that the trim percentage would be the same (where you place the weight). However because you would need less weight in fresh water you would have to know the difference and place your weight accordingly. You usually add approximately 1kg per 45 kg total weigh.

 

[jagfish]

Hi mania
Thanks for that. I don't mean finding the proper weighting. I'm talking about the weight distribution to achieve a horizontal position (trim) in water.

Assuming we have the weighting correct for seawater and our current exposure protection...

 

[terrasmak]

Tricky subject , i get to try it out soon. I know my setups for salt and im heading to fresh very soon .

 

[Walter]

Weight placement is not that critical.

 

[terrasmak]

Weight placement is not that critical.

Unless your looking to have perfect trim .

 

[Walter]

Are you really that equipment dependent? It's better, IMO, to rely on skill.

 

[terrasmak]

Rely on skill when your equipment screws up. Till then its better to have your equipment set up properly. Why would you want to fight Padi Trim (bad trim) the whole dive when with a little time you can have it set properly.

 

[Walter]

There's no fighting involved unless you use ankle weights. Placement is a null issue. Put them where ever you want, it makes so little difference that I never notice.