OK, ............I'm jumping into this thread.
The upside down mushroom is a big No-No.
Whenever a diver is in an overhead environment, that diver needs to be certified in either cave, wreck, or cavern diving technique. I understand there are many professional diving certifying agencies around the world, and most of them differ slightly in their rules and definitions, but here in the states a basic scuba or freediver is not to swim under an overhead environment. If a problem should occur (say the diver gets suddenly spooked by a big fish or another diver), that diver needs a direct ascent path straight up to the surface and not be subject to any type of required lateral swimming.
In Florida we have a lot of fresh water cave systems that are quite beautiful, but just as dangerous. As I posted in another thread not too long ago, I had to pull the lifeless body out a young girl who was not cave certified out and to the surface. She survived but I bet she won't try that again!
Jim
P.S. If I have to bring your body up, ........I will drop your mask and weight belt, then go back for it later and add it to my collection.
There is an unspoken agrrement amongst cave divers that goes like this, "If I have to retreive your body, I get to keep your gear because a dead cave diver doesn't need his gear anymore".
