Google's Ocean layer, which was introduced last year, is filled with hundreds of placemarks, from natural features like coral reefs to manmade shipwrecks and geographic ridges and chasms. The data comes from organizations including the National Oceanographic and Atmospheric Administration and the International Union for Conservation of Nature. Here's what you can do with it:
Double click on the "Explore the Ocean" layer and it will fly you to my Ocean Overview video and ten focus areas with National Geographic video clips. Other layers include dynamic sea surface temperature, Census of Marine Life data, Marine Protected Areas, shipwrecks, dive and surf sites, Arkive images, Planet Earth footage from the BBC, and much more. You can even visit a 3D model of the undersea laboratory Aquarius and fly to the Titanic and follow the expedition that discovered it.

Even more, they've begun work with Sylvia Earle's Mission Blue Foundation, which is attempting to create a series of "Hope Spots," protected marine areas. Eighteen of those areas are represented in Google Earth now, so you can visit them, learn about them, and learn what you can do to ensure their health.

There's even a tour:
We've also created a narrated tour featured in the Ocean Showcase to introduce you to eight of the regions proposed for protection: the Eastern Pacific Seascape including the Galapagos Islands, the Gulf of California, the Mesoamerican Reef in the Caribbean including Belize, the Sargasso Sea in the mid-Atlantic, the Chagos Archipelago in the Indian Ocean, the Coral Triangle, the Ross Sea in the Antarctic and Gakkel Ridge in the Arctic.

The open feel of Zooming around the oceans is new and unexpected--think of it as the interactive version of a great BBC nature documentary. They've added it right into Google Earth, so all you have to do is open it up and start zooming.