DEEP DIVING
The lure of diving deep is there. Cruising at 100' on a wall in the tropics that descends to 3000' has a mystical attraction to most divers. The temptation to descend further is so inviting it becomes dangerous. Is it the exhilarating feeling obtained when one cheats death or just plain nitrogen narcosis? With the introduction of computers more and more divers are taking the plunge to dangerous depths. The decompression tables would not allow extremely deep dives because of the lengthy stops that had to be made on the way to the surface.
Many feel the maximum depth for an experienced diver should remain at 130 feet. There are many reasons for that limit:
The pressure at 132' is 5 atmospheres absolute. The oxygen breathed at that depth is at a partial pressure of 1.05 atmospheres. At deeper depths oxygen poisoning becomes a real possibility.
A diver's air supply is cut to 1/5 of its normal amount.
Nitrogen is at a high enough partial pressure to cause significant intoxication.
Any contamination in the air supply, such as carbon monoxide, carbon dioxide, oil vapors, etc. are 5 times more concentrated.
Decompression may be required since the bottom time limit for that depth is only 10 minutes, and that counts the descent time.
It is darker and devoid of most color.
Because there is less light, there is less life.
And, if an emergency should occur getting to the surface at 1 foot per second is quite difficult.