I'm wondering what would be most effective ways to improve my air use in currents?
By way of background, I'm a fairly novice diver, with only 40 dives. My air use in normal conditions tends to be very good. Diving a regular 12L tank, I usually come back with close to half a tank at the end of permitted dive duration or when at least one person in the same dive group is down to 50 bar. This is probably due to being very small rather than any particular achievement of mine. I also seem to be able to breathe very slowly and deeply underwater. I am not superfit and because of my size I struggle with the size and weight of a 12L tank, especially on entries and exits.
On a liveaboard I did earlier this year I was given a 10L tank, which made dealing with gear much more pleasant. I was still coming back with more air than others, except the instructor, and was enjoying the dives much more. Recently, I was diving on 8L tanks on reasonably shallow dives (<20m) and was coming back with just a little less air than most others on 12L tanks and a little more than some. I was much more comfortable both in and out of the water and less tired after the dives.
Because my diving experience is so much more pleasant with the small tanks, I'd like to use smaller tanks in the future when they are available, however I am worried about limiting the group's bottom time if I am the first to get to the turn around air point. In normal conditions it doesn't seem to be an issue, but as soon as there is a current, my air use goes up pretty dramatically. I don't know that it goes up more than others, but if I'm on a smaller tank, I'll be burning through air pretty quickly.
So I'm hoping for a way to improve air use in currents to minimise these issues. Are there any exercises that I can do? I've been trying to do more fast/power walking (my knees don't seem to like running) but am not sure whether it is the right thing. I can't figure out whether it is a matter of leg muscle strength or aerobic fitness or something else? I'd be grateful for any ideas.
(All help appreciated, but please don't say "don't dive in a guided group", I know it is a possibility for the future, but I'm not confident enough yet!).
By way of background, I'm a fairly novice diver, with only 40 dives. My air use in normal conditions tends to be very good. Diving a regular 12L tank, I usually come back with close to half a tank at the end of permitted dive duration or when at least one person in the same dive group is down to 50 bar. This is probably due to being very small rather than any particular achievement of mine. I also seem to be able to breathe very slowly and deeply underwater. I am not superfit and because of my size I struggle with the size and weight of a 12L tank, especially on entries and exits.
On a liveaboard I did earlier this year I was given a 10L tank, which made dealing with gear much more pleasant. I was still coming back with more air than others, except the instructor, and was enjoying the dives much more. Recently, I was diving on 8L tanks on reasonably shallow dives (<20m) and was coming back with just a little less air than most others on 12L tanks and a little more than some. I was much more comfortable both in and out of the water and less tired after the dives.
Because my diving experience is so much more pleasant with the small tanks, I'd like to use smaller tanks in the future when they are available, however I am worried about limiting the group's bottom time if I am the first to get to the turn around air point. In normal conditions it doesn't seem to be an issue, but as soon as there is a current, my air use goes up pretty dramatically. I don't know that it goes up more than others, but if I'm on a smaller tank, I'll be burning through air pretty quickly.
So I'm hoping for a way to improve air use in currents to minimise these issues. Are there any exercises that I can do? I've been trying to do more fast/power walking (my knees don't seem to like running) but am not sure whether it is the right thing. I can't figure out whether it is a matter of leg muscle strength or aerobic fitness or something else? I'd be grateful for any ideas.
(All help appreciated, but please don't say "don't dive in a guided group", I know it is a possibility for the future, but I'm not confident enough yet!).