Having just toyed with deeper stuff, 85' a few times, I've noticed some specific "sensations" at that depth. The first being how heavy I feel when I'm at that depth, almost feels like the water's gettin thinner and you're falling through it. The next is the spooky feeling of not being able to gauge how deep you are when you can't see the bottom, I know, get a Sunto thingy:) What other noticeables can I look forward to as I get further, Noah

The thing most obvious to me is the pressure. I'm a bit claustrophobic and once I start to squeeze I have a hard time staying calm and relaxing. I would say the biggest thing is not pushing it to hard when going deeper than your used to. I hope others who are more experienced than me,,, RZ,,GR,, Jason,, will chime in and give their thoughts.

I really haven't noticed squeeze much, other than the normal chest compression, maybe I haven't gotten deep enough yet to hit that pressure wall I've heard about?

No you have,,, I was getting squeezed that day we where in 65. I think I am just bother more by it being clostrophic.

The air in your chest will dissapear and you will feel like you have none to spare. Diving deeper will wear you out fast.