I'd've thought that the majority of these locations will only be being accessed by cave divers, who have a vested interest in A) having the ropes there as a saf

I'd've thought that the majority of these locations will only be being accessed by cave divers, who have a vested interest in A) having the ropes there as a safety mechanism and B) not leaving unnecessary lines in place to avoid confusion. Not my field, but it sounds like the sort of problem that will be self-policing.