Google Maps have teamed up with environmental scientists at Catlin Seaview Survey to explore the seas in locations like the Great Barrier Reef, the Molokini Crater, and the Apo Island marine reserve for starters.

Try it yourself, have a look at Oahu, Hawaii, Hanauma Bay

For more locations please click the link below :
http://productforums.google.com/forum/#!topic/gec-our-oceans-seas/7BjcFAzpBMM