Then there's the matter of nitrogen bubbling up in your joints if you ascend too fast. Pain can lead to death pretty quickly if you're careless. But it's easy to avoid. After class we drive to a nearby backyard pool, suit up and go down. Breathing underwater for the first time is a fine little miracle.
Scuba gear is both exquisitely complex and sublimely simple.
A low-pressure hose goes from the tank to the BCD so that, with the touch of a button, you can inflate or deflate the vest in small bursts. This allows a weight-belted diver to neutralize buoyancy underwater or bob on the surface. Smith puts us through our paces in the pool. We remove the regulator from our mouths, drop it, then recover it. We share air, simulating an emergency.