As this keeps popping up, I will also continue to remind people of the changes in diving through the decades.
Safety Stops became fashionable in the 1990s as a result of data, which was proved wrong, that micro bubbles may contribute to DCS. Since this has been proven wrong, Safety Stops have stayed fashionable as a method of adding a safety margin to the NDLs and giving a controlled break in the ascent, e.g. check for boats and things at the surface. They are not mandatory in any algorithm I know of nor are the penalized by most if not all computers, except maybe the Suunto algorithms :depressed:
Ascent rate used for much of recreational diving history was 60ft/min, not the 30ft/min. The reasons chosen for the 60ft/min rate are simplistic math and not a basis in DCS. It has valid basis to use the 30ft/min rate to reduce risk to DCS.
We, the pre 1990 divers, have completed many dives past 100 using No Safety Stop and an ascent rate of 60ft/min. This was a normal dive profile for me for much of my diving life. One difference was that we had a conservation built into us by using square profiles to describe our multi-level dive when using dive tables. I have had numerous square profile dives to NDL, though.
As we have better scientific and empirical data, we have learned to use the 30ft/min rate and built a safety margin into our plan by using a safety stop. In an EMERGENCY, I am very willing to throw out the 30ft/min rate and safety stop as needed. In an emergency, I will if needed, surface as fast as necessary. If I get the bends, I will deal with that on the surface. I also suspect it will not be a major hit as I was not over NDLs, remember this is a Recreational profile plan. I have NEVER run out of air unexpected by the way and have very good situational awareness.
Also, with regard to air supply, every foot ascent on my gas will get me a foot closer to the surface. A free ascent from 100 is a big deal. A free ascent from 30 should not be to any proficient diver. Yes it is best to have gas all the way to the surface with a safety stop, but in an EMERGENCY, I will take what I can get and deal with it. I suspect that his is the reason we do not hear of deaths or DCS very often from emergency ascents, they are much closer to the surface then the dive depth when they lose gas supply, when in a known emergency! I, as any experienced diver can attest to, have seen many divers breach the surface out of air without further issues. While this is less common now, it used to be quite common on the boat.