The good people over at TONSTURM has released a water library that is definitely worth checking out:
TONSTURM 07 | The Sound Of Water
with this new soundpack you get all sorts of deep, splashing, bubbling and bursting water sound effects recorded during extensive field recording sessions above and under the surface of water. The underwater sounds were captured with the mind blowing hydrophone stereo rig from Sonar Surround. Recorded in high definition 192 kHz, 24 Bit.
Full article and samples here.