In one of the earlier reviews, the anonymous reviewer mentioned breathing air in an air pocket in the hull of the ship. Don't do it. While he may have survived to tell his tale, these underwater air pockets are notorious for being toxic, because of the corrosive effects of the seawater on the ship. Some caves are known to contain toxic pockets, as well, because of decaying coral or other organic material. They are also low in oxygen, as there is really no way to replenish the oxygen in that air space. With each breath the CO2 content goes up and the O2 down. As far as my comments on the ship, I was disappointed by the scarcity of fish around the wreck. The most interesting part was the part I didn't see. I found the small entrance to the engine compartment late in the dive and didn't enter because of bottom time limitations. I'll definitely head straight for that the next time to see what's lurking down there. This is not for the inexperienced. Overhead environments and confined spaces can be extremely dangerous for many reasons.