edasque

Well, the shift in buoyancy hasn't been a problem, it was my weighting that was. I was way under weighted even with my CL at minimum volume (inhaling).

I have to figure out the best weight and weight distribution for those conditions first. I hope to get 0.7 working at this point as I don't want to be around .4 at those depth (not descending), that's too close to normoxic for my comfort.

I feel that .4 at the surface is ok for a short period of time, knowing that you're going to get to 30m quickly (4 ATM) and your PPO2 is going to be high at that point before you switch to your bottom PPO2 but wouldn't you breathe out .4 at 3 meters very quickly towards normoxic (which could really mean hypoxic if you take into account potential O2 sensor linearity problems ?)