One Summer early in my commercial diving career, I was part of a dive crew that spent several weeks doing almost daily work at 209,' diving air. The jobs were usually short duration ( :5 -:12 ), so to minimize our chamber deco time, we would load up our commercial harness-style weight belts with lead pigs, & rocket to the bottom. I recall the first several dives to be head-spinning adventures, but doable, and after a time, we started to acclimate to the exposures. Mind you, we had unlimited gas supply via umbilical, communications, bailout supply, standby diver at the ready, a rack operator to run our dive, and a chamber to deco in. Later in my career, I had occassion to do "Bell-Bounce" dives, where the diving bell would be lowered to working depth at atmospheric pressure; when ready, the Bellman would "blow down" ( open a valve of lp gas to pressurize the interior of the bell ) to an equivalent gas pressure to match the ambient water pressure at working depth. When the pressure equalized, I'd slip out of the Bell, do my work, return & get back inside. Once we were squared away ( umbilical stored, hatches closed & dogged ), "Topside" ( the Dive Supervisor & crew ) would start our "Deco" by slowly venting gas from the bell as per the table we were running, while the bell was winched to surface & re-mated with the deck decompression chamber, into which we'd transfer to complete our deco obligation. Again, this type of diving had the advantage of being surface-supplied & controlled.
Best of all, we were paid very good money!
And those methods, my friends, are the only way you'd ever find this cat doing "bounce dives."
Regards,
DSD