Thalassamania:Why bother? Having air in your tank when you get back on the boat is potential extra deco that you could have taken and didn't. I operate on a very strick Bingo Air system (Rock Bottom to you DIR types) which includes my right to suck my tank down to 100 PSI or so above ambient whilst directly under the boat and holding at 10 to 20 feet. And the DM who has a problem with than can go perform an unnatural act.
:thumbs_up: