When someone jumps into a cave and lands at the bottom with a parachute...what's next? How do they get out?

I was watching Planet Earth: Caves and it shows a bunch of people just nonchalantly jumping into these huuuuge caves in Borneo and Mexico and such. What I don’t understand is how they get out. I’m trying to google it and find an answer but I’m yielding no results. I’m very curious. Anyone know?