How an Underwater Habitat Benefits Marine Science; October 1996; Scientific American Magazine; by Miller; 2 Page(s)

Scuba divers joke that there are two ways to avoid decompression sickness, the rare but dreaded "bends": don¿t go down, or don¿t come up. In a sense, an underwater habitat is a way of making the latter option possible, at least for a few weeks.

To understand how such an option becomes possible requires a little knowledge of physiology. Breathing air in the relatively high ambient pressure of the underwater environment causes a diver¿s blood and tissue to accumulate excess inert gases--mostly nitrogen. The amount of excess gas absorbed by the diver¿s body depends on the depth and time spent underwater. Thus, simple physics dictates how long a diver can remain at specific depths without risking the bends, which occurs when the excess inert gas absorbed during a dive bubbles out of a diver¿s blood and tissues as he or she ascends and, consequently, the surrounding pressure declines.