I would love to see the IANTD nitrox manual suggesting/teaching PPO of 1.8
PPO2 1.6 MAX on recreational dives (Warm water and low workload )!!!!
I'd like to see it as well. It's possible he's just going on memory and thinks it's 1.8.
I'd double check that.
How old is that IANTD manual?
Last I new, Joe Dituri was living on Oahu and he may still have one of the old ones.
I got mine from the author, who I did my Advanced EANx Instructor crossover with; the founder, Instructor Trainer #1. My Instructor card is dated 09 June 2001 (#3611).
NITROX MANUAL: Complete Guide to Nitrox Diving
by Dick Rutkowski
1st Edition - Dec '89
Revised
Sept '90
Nov '93
Mar '94
Oct '96
Copyright '94 by H.I., Inc.
flipping fairly quickly through the pages; page 37, in Dalton's Law, top paragraph -
"...It must be determined what PO2 is being inhaled to avoid exceeding the safe physiological limits of oxygen and prevent CNS O2 toxisity. This amount of oxygen is 1.6 ATA/Bar (A) for 45 minutes. This will be explained in a later chapter."
page 40, still in Dalton's Law; most of the page is Figure 7, the
NOAA OXYGEN PARTIAL PRESSURE and EXPOSURE LIMITS for NITROGEN-OXYGEN MIXED GAS WORKING DIVES.
the top section is labeled "
Normal Exposure Oxygen Partial Pressure Limits" with single duration and 24-hour duration times for 1.6-0.6, in one tenth increments.
the bottom section is labeled "
Exceptional Exposure Limits" with single duration times for 2.0-1.3, in one tenth increments.
if you are still following along, those limits are; 30, 45, 60, 75, 120, 150, 180, 240. The cliff note are that; 2.0 has an Exceptional Limit of 30 minutes, 1.6 has an Exceptional Limit of 120 minutes, 1.3 has an Exceptional Limit of 240 minutes.
three paragraphs later, this is the entire paragraph -
"Exceptional Exposure Limits are for use only in lifesaving operations."
page 45 starts the PHYSIOLOGICAL IMPLICATIONS OF OXYGEN AND OXYGEN LIFE SUPPORT RANGES.
3rd paragraph -
"For normal diving operations, oxygen partial pressures must be maintained between .016 and 1.6 ATA/Bar (A). During oxygen decompression and recompression therapy, higher levels of oxygen can be tolerated. Under these circumstances, divers are at rest and/or under controlled conditions in a recompression chamber.
EXCERCISE GREATLY REDUCES A DIVER'S TOLERANCE TO OXYGEN. Oxygen levels above 1.6 ATA/Bar (A) should not be used during a normal dive."
page 46 is titled
Oxygen Limits for Life Support Systems. Near the bottom is an "example" table for ATA's 1, 2, 3, 4, 4.5, 5, 6, 7.6, where 7.6
on AIR is 218 fsw and PO2 1.6 with an *. Higher up in the "example" table 5 ATA / 132 fsw is 1.6* for NNI and 4.5 / 114 is 1.6* for NNII.
At the bottom of the page is; "*
1.6 ATA/Bar (A) O2 limit for a working diver"
I underlined that last bit; all other emphasis is the way it is in the book.
page 47, once again most of the page is Figure 7, the
NOAA OXYGEN PARTIAL PRESSURE and EXPOSURE LIMITS for NITROGEN-OXYGEN MIXED GAS WORKING DIVES, again with the "
Exceptional Exposure Limits"
now skipping to the back of the book
Appendix E, Table E-2 is the NOAA NITROX I DECOMPRESSION TABLE (
32%) -
I am tiring of this transposing, but I will just give the info for a 20 minute dive to 150fsw; 4:40 ascent time to first stop at 10fsw, 4 minute stop, repetitive group H.
Appendix F, Table F-2 is the NOAA NITROX II DECOMPRESSION TABLE (
36%) -
a 30 minute dive to 120fsw; 3:40 ascent time to 3 minute 10fsw stop. There is no repetitive group as repetitive dives are not allowed after 36% exceptional exposure dives.
My crossover was a "one on one" few days with Hyper Dick. He read between the lines for me. He told me that with my significant major joint/bone injury history (compound fractured right wrist, shattered right patella, seriously broken right elbow & titanium reinforced tibia, completely rebuilt right shoulder, un-repaired right hip injured in most of those different incidents) I should not consider deco diving. He said that given my prowess in the water, gently gliding down to the props of the Duane for a pic of a Bull Shark or Goliath Grouper on 36% was something I could consider. Just no chasing!
