Deep wreck and cave diving is similarly dangerous (and was much more so before the adoption of Trimix by the technical diving community). There have been numerous fatalities among rescuers trying to recover corpses of other dead divers, too. I decided after reading a fair bit about this that even if I can afford to dive like this ($20k+ for equipment, $10-20k+ for training, and $500+ per dive for helium-based gas fil…
A wonderful article about the attempted recovery of a body in a deep cave