Datacenters sitting in and on barges out at sea which use wave motion for power and ocean water for cooling are are things google has been mulling for a long time according to a recently descovered patent application.
An 18 month old application by the company has surfaced in the US patent office. The application abstract says: "A system includes a floating platform-mounted computer data center comprising a plurality of computing units, a sea-based electrical generator in electrical connection with the plurality of computing units, and one or more sea-water cooling units for providing cooling to the plurality of computing units.
The full application can be found here
In January 2008 services start up company IDS proposed that it would buy decommissioned container ships moored at piers in ports around the world as floating datacenters which would cut cooling costs by 30%.