Just to be clear, Sur-D-O2 tables are different than decompression tables with all in-water decompression. Water stops are often augmented with high PPO2 and deep mixes are also often on the rich side. Getting the diver out of the water and comfortable is a huge safety reward and overall decompression is faster since the diver can safely breath much higher O2 levels than in the water. This also increases productivity of the dive operation since more divers can be cycled per day.
In the vernacular of the commercial diving industry, any non-saturation dive is a bounce dive, though usually referring to deep mixed gas dives with and without a small non-sat bell system. It is not unusual for a mixed gas bounce dive operation to include two double-lock chambers for Sur-D, 3-4 LP compressors (175-250 PSI), a portable gas shack/control room, and dozens of 6 to 12-packs — 6-12 commercial-size 200-300 Ft³ HP cylinders of pre-mix and pure O2 manifolded into a protective cage.
I have never seen or heard of a bell/SDC (Submersible Decompression Chamber) that did not mate with a DDC (Deck Decompression Chamber) though there are all kinds of weird systems out there. I have heard of divers who were contaminated with hydro-carbons on the bottom and using a small bell bounce dive system being switched from their all-chamber decompression schedule to a Sur-D-O2 table. It is very dangerous to run high PPO2 decompression in a “dirty” chamber due to fire.
Very few non-sat bell systems have the size or capability to “clean up” the diver before entering the chamber so the supervisor will run the equivalent Sur-D water stops in the bell, vent them to the surface, undress and clean them up, and blow them back down in the deck chamber to complete the Sur-D-O2 table that they were switched to. I doubt there are any supervisors that would willingly chose Sur-D over all decompression in a bell and chamber without a problem like this.
All the Sur-D tables I have seen do pay a penalty for the short surface interval over bell/chamber based tables on equally high PPO2, but the risk is well worth it when considering hypothermia, OxTox, and less efficient outgassing in the water… to say nothing of the misery factor and holding up the operations.
In the vernacular of the commercial diving industry, any non-saturation dive is a bounce dive, though usually referring to deep mixed gas dives with and without a small non-sat bell system. It is not unusual for a mixed gas bounce dive operation to include two double-lock chambers for Sur-D, 3-4 LP compressors (175-250 PSI), a portable gas shack/control room, and dozens of 6 to 12-packs — 6-12 commercial-size 200-300 Ft³ HP cylinders of pre-mix and pure O2 manifolded into a protective cage.
I have never seen or heard of a bell/SDC (Submersible Decompression Chamber) that did not mate with a DDC (Deck Decompression Chamber) though there are all kinds of weird systems out there. I have heard of divers who were contaminated with hydro-carbons on the bottom and using a small bell bounce dive system being switched from their all-chamber decompression schedule to a Sur-D-O2 table. It is very dangerous to run high PPO2 decompression in a “dirty” chamber due to fire.
Very few non-sat bell systems have the size or capability to “clean up” the diver before entering the chamber so the supervisor will run the equivalent Sur-D water stops in the bell, vent them to the surface, undress and clean them up, and blow them back down in the deck chamber to complete the Sur-D-O2 table that they were switched to. I doubt there are any supervisors that would willingly chose Sur-D over all decompression in a bell and chamber without a problem like this.
All the Sur-D tables I have seen do pay a penalty for the short surface interval over bell/chamber based tables on equally high PPO2, but the risk is well worth it when considering hypothermia, OxTox, and less efficient outgassing in the water… to say nothing of the misery factor and holding up the operations.
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