David Novo
Contributor
I don't think the answer at this point is to change equipment as a back inflate BC is not that big a difference from a BP/W. Maybe the depth of your diving is adding extra stress that you do not need at this point, are there sites where you can practice that are less than 25 m and closer to say 15 m. Being stressed can significantly increase you air consumption and obviously depth has a significant effect as well. Have you done a proper weight check and have you positioned the tank to get your best horizontal trim. At this point you appear as if you are not totally comfortable and adding the increased complexity of doubles is unlikely to help. Do you have any mentors that can help you.
Yes, I have done a proper weight check and that does not seem to be the issue. I am inhaling fast but have been having trouble, reducing that (despite exercising regularly), while exhaling slow. I can dive at 15m for an hour with the same tank, so the issue is really on deeper dives (which are the ones that involve less than 2 hours by car each way).