Old question,maybe?

[Mr Small]

This has probably been asked before,but here goes anyway.If I where to switch from a 15l steel cylinder to a 12l steel cylinder,would I be able to take lead off or would I have to add it?I recon I would need to add more weight to get down at the start of the dive but would then be well over weight at the end?Many thanks in advance.Stu.

 

[MyDiveLog]

It depends on the bouyancy characteristics of each tank, which should be published. Another, less precise approach, would be to fill each tank. The 12L tank will have less air & therefore less weight at the beginning of a dive, but the manufacturer may have compensated by adding slightly more steel.

Another idea: Hook one up to your BC, put it in the tank and BC in the pool (without wearing it). Inflate the BC until it is neutrally bouyant. Remove it from the pool, switch tanks (without deflating the BC) and see if the bouyancy is different.

Of course you could simply re-do a bouyancy check wearing the new tank, but that would be much less esoteric (and interesting)!