Underwater Rock Runs

I just noticed this really cool workout that I WON'T be doing anytime soon from the T-Nation Third World Workouts article:

Underwater rock runs

Our boats would be anchored about 100 yards off the beach, in around 18 feet of water. We generally used these as the markers, but the workout can be performed just as easily if you run parallel to a beach. You can also use the deep end of a pool. (Just check with the lifeguards first so you don't cause an incident.)

Each two-man team picks a large rock and races to the boat with it. The first man carries the rock while the second man swims above him on the surface. Then they switch. Once they reach the boat, a mooring line is dropped in the water and the rock must be carried up the line onto the deck of the boat. From here, knock out 50 pushups, throw the rock back into the water (check for swimmers first), and return it to the beach.

18 feet deep!? I think by the time I got down there I'd have to come right back up. I also get water up my nose no matter what I do, so I can't imagine this is the workout for me, but man it sounds like fun if you can swim. How the heck one climbs a mooring line while carrying a heavy rock though, I have no idea.