I figure everyone covered all the major ways to get better gas consumption.
I can hang with any guy on the same size tank, but have made dives with one or two experienced and well conditioned ladies that beat me bad!
So I learned a few ways to cheat!
1. Whenever possible pick a higher plane in the water column than your buddy, as high as the visibility will allow.
2. Only drop to the bottom when there's a good reason, such as pulling yourself along rocks when in strong current, (non-coral covered of course.) You can do this in sand as well, with a knife or even with your hands... kick forward and drag for a short rest, then kick forward again.
3. Always use the anchor line or down line, to descend and pull down with your arms, even if the current doesn't seem very strong.
4. Never volunteer to carry the float line or the team lobster bag. Make your buddy the pack mule.
5. In currents always shadow structure like wrecks, or bridge pilings.
6. Keep your head down in current, don't let it lift you into a bad trim position.
7. If a dive requires a back track, such as to an anchored boat, plan to do it along the top of a reef line. This will help cover more new ground as well if you are hunting fish or lobsters.
8. Get a good compass and learn to navigate with it, and also navigate naturally. Nothing wastes more gas than being lost or taking the long route.
9. If you still can't beat or keep up with a buddy, or get a bigger tank... admit defeat and have them wear a long hose and leach off of him/her! Do it in the middle of the dive or on the deepest part. Don't wait until you are low and have to ascend on the long hose. (That's also when it will make you look bad!)
Chad