Brussels/San Francisco  - Academics and armchair explorers were as of Monday offered a unique insight into the world's seas through a new release of Google Earth, which now also features satellite imagery, photos and videos of the planet's oceans.

The 5.0 version of the popular downloadable software was launched in San Francisco. The project was also presented in a number of European cities, including Brussels, where the European Commission is contributing by providing its own marine data.

"Google Ocean ... will further encourage the protection of the marine environment, which is such a vital and rich natural resource," said the European Union's maritime affairs commissioner, Joe Borg.

Launched in 2005, Google Earth is a free internet application that combines satellite images and users' content about the planet.

Its latest version also offers users a virtual dive beneath the waves, allowing them to explore ocean beds, marine life and even shipwrecks, through 20 "layers" of information.

By clicking on "placemarks" scattered around the seas, users can access additional photos and videos provided by, among others, the British Broadcasting Corporation, National Geographic and legendary French ocean researcher Jacques-Yves Cousteau.

Google officials admit that the parts of the ocean that currently offer any level of detail are limited, but hope that conservationists, institutions and individual users will update it with more content after its launch.

And while they would not disclose the costs involved in the two- year project, they acknowledged that Google Earth is designed to help "drive web usage". Google makes most of its money by receiving a share of the money paid by advertisers to publicize their products over the internet.

Other novelties included in the latest release of Google Earth include sea temperatures, a three-dimensional image of Mars and a "virtual time travel" feature allowing users to track the progress of major building sites or the melting of glaciers.

Google Earth 5.0 can be downloaded after 1800 GMT at http://earth.google.com. (dpa)