So 137 depth there is stupid.. That seems like a pretty clear and definitive answer/opinion - rather than pure speculation. I'm not too familiar with that site myself.
At what depth would not be stupid, in your opinion?
How many feet away was the body from the "smart" versus the "stupid" distance/depth?
We don't know the divers intentionally dived to 137, only that's the depth one body was found. The cavern is big. This is where I'd really like to see the dive-logs. While a 137ft open-water dive on a single AL80 tank is risky, doing one in a cavern/cave is where it becomes stupid.
I dove once on a single tank, air, at 130ft in open-water. My "older and wiser" self isn't comfortable with that. These days, I have redundant air (19cu or bigger) on EVERY dive, even at 15ft. A pony tank and extra regs may seem pricey, if you think of it like an insurance policy with low reoccurring costs, it's rather inexpensive. At 100+ feet, it's a no-brainer to use two tanks, but that's also because I dive sidemount, and have those skills/equipment. Sure, maybe I can CESA from 60ft, but I'd rather save myself the trauma of almost drowning.
Besides for agency standards and potential for narcosis causing problems.. at 5atm the “average” unstressed diver can make an al80 last 15minutes. [77cf/(1cfx5ata)] Thats not accounting air used getting there and having enough to get back to the surface at a safe speed. Now put a diver under stress and his air consumption doubles so the tank lasts only 8 minutes, then make him share air with another stressed diver who had a failure and the tank gives you 4 minutes. Then account for a need to do a 4.5 minute ascent to arrive safely at the surface as well as subtract what air it took during the decent to depth…. If nothing goes wrong you can make the dive without issue, but you’re gambling on your life that you and your buddy won’t have a regulator problem and/or won’t have anxiety if you end up sharing air..
My 130ft dive had a bottom-time of almost exactly 15 minutes (excluding descending and ascend time). I think I ended with around 750psi, with 5min safety stop.
Of course with stress, entanglement, air-share, regulator-issues, etc ... that was risky by my standards. In terms of "3 strikes you're dead" I'd rate my own dive a 1.5 strike dive, given no backup lights, no redundant air @ 130ft, and inattentive dive-buddy. Not cool, but I don't do that anymore.
