One trick you can use early on, is to carry multiple air tanks and swap them out, which opens up quite a few possibilities :P Only trick to this is, they have to be equipped to refill as well, so you need to cycle them when you surface.
One trick you can use early on, is to carry multiple air tanks and swap them out, which opens up quite a few possibilities :P Only trick to this is, they have to be equipped to refill as well, so you need to cycle them when you surface.