Posted by northcoast diver on February 12, 2005 at 13:32:40:
In Reply to: deep diving advice and books posted by Gregg M. on February 11, 2005 at 23:13:03:
Step 1. Stop diving deeper than 100 ft (I know, you will all call me a hypocrit for saying this).
Step 2. Take IANTD or TDI or GUE training for Advanced Nitrox and Staged Decompression (this is where I disagree with many of you, in that I believe they are all good agencies, and that no one is better than any of the others).
Step 3. Decide for yourself if you want to move on to Helium training.
You can safely dive in the range of 100 to 150 ft without helium mixes in your breathing gas (although some groups disagree with this statement). But diving in this range is not really covered in the non-technical agencies (NAUI, PADI, SSI, YMCA).
With helium mixes, you can go as deep as you want. 200 ft becomes a one hour total-dive-time dive. 250 ft become a one-and-one-half hour TDT dive. 300 ft becomes a two hour TDT dive, so you better have a pee valve on your wetsuit.
DIVE PLAN (Example)
Surface interval = 5 day 0 hr 0 min.
Elevation = 0ft
Conservatism = + 3
Dec to 150ft (3) on Nitrox 25.0, 50ft/min descent.
Level 150ft 17:00 (20) on Nitrox 25.0, 1.38 ppO2, 141ft ead
Asc to 70ft (22) on Nitrox 25.0, -30ft/min ascent.
Asc to 60ft (23) on Nitrox 50.0, -30ft/min ascent.
Stop at 60ft 1:00 (24) on Nitrox 50.0, 1.41 ppO2, 26ft ead
Stop at 50ft 1:00 (25) on Nitrox 50.0, 1.26 ppO2, 20ft ead
Stop at 40ft 2:00 (27) on Nitrox 50.0, 1.10 ppO2, 13ft ead
Stop at 30ft 3:00 (30) on Nitrox 50.0, 0.95 ppO2, 7ft ead
Stop at 20ft 1:00 (31) on Oxygen, 1.60 ppO2, 0ft ead
Stop at 15ft 7:00 (38) on Oxygen, 1.45 ppO2, 0ft ead
Asc to sfc. (38) on Oxygen, -30ft/min ascent.
Off gassing starts at 96.1ft
OTU's this dive: 56
CNS Total: 23.1%
86.6 cu ft Nitrox 25.0
9.5 cu ft Nitrox 50.0
5.9 cu ft Oxygen
102.1 cu ft TOTAL