[narvval]

You could pass a tie-off if you had two carabiners, as you do in via ferrata. Don't know about the entanglement risk though... I'm not a diver but that sounds way less dangerous to me than losing the cable altogether, since worst case you could just release the carabiner

[gaius]

Another thing to consider is this is just a guideline - 2-3mm nylon, fixed in place often just be wrapping around a handy outcropping. If you tug on it with any force it will come loose. And then you and everyone in the cave with you are in a lot of trouble.

[wallflower]

Another thing that guide mentions is that if the nylon guideline is cut, it will rapidly snap and retract and spool up (kind of like a fishing line).

Also I read an accident report of some divers who survived a silt out condition, they spent a lot of time carefully figuring out what direction they should follow the rope out to exit the cave in places where it has been wrapped around a stone a few times to anchor it.