IndigoBlue
Contributor
armyscuba:Yeah Blue,
Air is all We got..Yep..We dive Doubles..We dive Everyday..Chamber is ready..and Hell it's Free..I don't need DAN on My deployment. We have some Great walls..You have to see them to believe them..We do surface swims or swim slots that lead to 600 and 700 meter drops..We sit at the wall and wait for submarines to pass. I did 4 dives today, the last being a night dive. Today was no more than 80 ft for Me. I try to be good and not venture past the 150 limit to often...
That sounds more encouraging to me than would be pushing the 1.6 PO2 limit.
NAUI RGBM Deco Tables reflect an NDL time of 6 mins for a 45 meter dive, like when you are "try[ing] to be good." The USN tables reflect 5 mins of NDL time for that depth. The two somewhat agree.
The more salient question is at what depth should your first 1 min deep stop be during your return? Most would say around half your MOD, which comes to about 75 ft.
Paradoxically, however, the RGBM Deco Tables show no need for a required deep stop on a dive to 45 meters if it is 10 mins or less (however a 2 min 10 ft deco stop on oxygen would be required). For such a dive for 15 mins, the first deep stop is at 30 ft, and for such a dive for 20 mins, the first deep stop is at 50 ft (all followed by oxygen deco). These first deep stops are 1 min stops. The USN tables do not reflect these deeper stops, and so the USN tables may be too aggressive.
For any diving to 45 meters or more, for a duration of longer than 6 mins, you would need to consult the USN dive tables for your required deco stops, however, since RGBM uses oxygen on the 20 and 10 ft deco stops for an air dive to 45 meters when longer than 6 mins.
That is what you are up against, when you venture to those depths.
If you stick to the traditional 130 ft recreational MOD, then your RGBM NDL time limit is 10 mins, and for such a dive, no deep stop is reflected on the RGBM deco table. That would be most divers' recommendation as well. My own recommendation is 100 ft, max. And when I dive to 100 ft, I stop at 50 ft for 1 min, 25 ft for another 1 min, and 15 ft for 3 mins.
Dive safe, and "be good."