I am not a diver. My impression of the dangers of cave diving are: (1) Low visibility, (2) Confined spaces, (3) Navigation (getting lost). Are there other concerns that would make cave diving more dangerous than other diving?

I can imagine a SEAL in front of a rescuee, a SEAL in back, and everyone tied together with short ropes. And the entire group following a separate rope for navigation.

Other than the panic induced by having your first dive be in a confined space with no visibility, I would think the more experienced SEALS (or specialty cave divers) would be able to get you out. Just don't panic. You would be dead in a second if you panicked.

Are there other concerns?