Thank you Don, that was well written and the advice is noted. Sorry about the loss of your friend.
It's interesting how divers can come up with the same technique without instruction. I guess there aren't many options, you need to sink without making a splash and the only way to do it is reduce buoyancy fast, and the only way to do that is exhale. I figured out this trick very early on hunting bajonao (porgy) in Cuba, they were big and almost impossible to get within shooting range. As soon as you'd dive on them they'd take off. So I used this emptying the lungs method. Of course this was in very shallow water, maybe 20ft. In deep water you don't need to use it, I think the fish don't spook because of the greater distance. I've never done this lung emptying since, I don't remember having gotten in trouble. I always use a floatline and float, with this way of doing it after the shot you immediately have to let go of the gun and shoot for the surface. Was Bill Kroll using a reel? I'm not advocating this method, just trying to find out if there was another factor that contributed to Bill Kroll drowning.
On a different but related note, I almost always exhale a little before I dive.





