Underwater Definition and 152 Threads

I'm curious about some fluid dynamics stuff, and my first series of questions I have are to do with how air rises out of water... Having done some scuba diving, I know that divers use bladders to achieve neutral bouyancy and positive bouyancy so as to hover or rise through the water. Now...

[SOLVED] Underwater barrier [?] Since I've been lookin a the concept and knowledge to what happens when the sound barrier gets broken and how it happens, it got me thinking about if the same thing can happen in water. i.e. If an object was to move faster than the water molecues could move what...