Soloist
Contributor
I would like to be able to get a reasonable / maximum amount of bottom time in the 40 to 50 m range whilst keeping the overall dive time to 50 to 75 minutes.
Even though it was aimed at me I thought the joke about letting Darwin's theory of evolution take its course was quite funny, that is why I "liked" it. Getting back to the original topic Neil is right to some extent, although I would use the words at minimal cost and minimal complication instead of "on the cheap". Nitrox 32 is limited to about 33m but gives a useful increase in NDL time compared to air. When diving to depths greater than 30m BSAC require a back up gas supply, some other dive centers / agencies require a personal pony or a spare cylinder on the shot line at say 6m. There are two things that limit your time at depth, quantity of gas and NDL. Suppose all you want is a bit of extra time and safety margin on that wreck that sits on the bottom at about 45m. What I envisaged was having 15L of air on my back but instead of having 3 Kg in my LHS weight pocket hang 12 L of Nitrox 32 complete with regs on my left hand D rings. I descend using the nitrox to about deck level say 25m, then I change regs and have a decent length of dive round the deeper parts of the wreck until my air is down to say 100 bar. I then ascend to less than 33m and change back to nitrox to extend my NDL and explore the upper parts of the wreck.
The above method means I get a good length dive, at all times have a good supply of back up gas and minimize my nitrogen build up.
Do you enjoy playing Russian roulette in the comfort of your home, strolling on the beach, at the pub or just when diving? Please get certified in decompression procedures and advanced nitrox.