violent water movement.
I learned alot reading all this. (that alot of this is way over my head. lol) What I did not see anyone talk about was "violent water movement." What could this be and how could it cause death? damage your equipment? current would be steady and not fast changing?
Surf zone and surge near a rocky shoreline or shallow reef come immediately to mind. Dive anywhere on the Pacific coast had you will see plenty of examples.