Maps go underwater now as Google has added panoramic imagery of Hawaii, Australia, and the Philippines. From the Google Maps Blog:
Find a sea turtle swimming among a school of fish, follow a manta ray and experience the reef at sunset. in the Great Barrier Reed. At Apo Island, a volcanic island and marine reserve in the Philippines, you can see an ancient boulder coral, which may be several hundred years old. And in the middle of the Pacific, in Hawaii, you can join snorkelers in Oahu’s Hanauma Bay and drift over the vast coral reef at Maui’s Molokini crater.
The images are stunning as seen in this video.
The feature works like Street View in Google Maps. And the images were captured using an SVII specialized camera while traveling at 4 kilometers an hour.
View the full collection of 12 dive sites at Google Maps Ocean.