but this isn't correct. if you're carrying 6 pounds of air in your tank, you need to be 6 pounds heavy at the start of the dive so that you can maintain your safety stop. That means adding 6 pounds of air to your BCD that you will remove throughout the dive. If he lost his weight pocket that contained 3 pounds of weight, he would only need to add 3 pounds of air to his bcd to be neutral, at the beginning of the dive. The problem would occur after 3 pounds of air has been used, when he wouldn't be able to main neutral buoyancy.I said “should have,” not “would have.”
Edit: OK, let me spell this out some more for the person who was confused by my post. "Should have" because if someone is properly weighted, then losing weight means going up. Not "would have" because if he's overweighted then perhaps it would not.