DA Aquamaster once bubbled...
The PADI Recreational Dive Planner REQUIRES a 3 min "saftey" stop for all to dives to 100 ft or greater as well as 3 minute stops for the last 4 time intervals for all lesser depths. This is quite consistent with what you are noting for the shorter half lifed compartments.
LOL. Yes, I'm aware of the rules for use of PADI RDP.
I just used that description of 3 minutes deco stop on GAP
with no conservatism as a shorthand way to indicate that multilevel dives planned on the RDP load up the fast tissues to a higher level than does just running out to the NDL at any single depth. Using the same setup conditions, the PADI single depth NDLs did not create any deco requirement whatsoever in GAP.
Perhaps I should have stated the less intuitive "planning multilevel dives on RDP may run 20 minute compartment up to around 70fsw". (Higher than DSAT'87 and Buhlmann '90 ZHL16B&C, but lower than Workman '65. This was even with using a 30fpm ascent rate to offgass the fast compartments a bit
more.)
DA Aquamaster once bubbled...
In my opinion a mandatory "saftey" stop is in effect a deco stop and we are really talking about overhead diving with some of the profiles allowed by the RDP.
The flip side of "every dive is a deco dive" is that "a few minutes of deco does not an overhead make".
I wouldn't classify any PADI RDP profile as "overhead"; the same way that I wouldn't classify deco imposed solely by running ZH-L16C with a gradient factor of 85 as an "overhead".
Indeed, since deco is a probablistic calculation, even 5 or 10 minutes of "required deco" doesn't really present very much of an overhead risk.
Don't blow away deco stops on a whim, but also don't be like the Rescue Diver student mentioned in another post that stopped for his Suunto's 3 min SS on the way up with a simulated casualty.