And folks who don't want to waste money on nitrox?
WHY NITROX?
Nitrox provides a lower percentage of nitrogen than ordinary air. In this way less nitrogen will enter the body at a given depth and decrease the risk of two nitrogen-related problems: decompression sickness (DCS) and nitrogen narcosis. Both DCS and nitrogen narcosis result from increased nitrogen pressure, the former from bubble formation on ascent and the latter from nerve inhibition at depth.
the decreased nitrogen percentage provides advantages,
1) as a time extender for dives to recreational depths, i.e., ability to dive longer at a given depth than allowed for by standard air tables, without increasing the risk of developing DCS;
2) to lessen the risk of developing DCS for dive profiles that adhere to the standard air tables.
3) can shorten the surface interval between dives
4) Increased safety margins if dived with a computer set to 21%
5) Feel good factor, some people say they dont feel as tired after diving with Nitrox
So how exactly is it a wate of time. Spend a couple of hours in a classroom, sit an exam, & maybe get to do some dives all for a couple of $.
Its not the most exciting course, I agree, but the benefits are worth the boredom.