1sockchuck writes: California startup Nautilus Data Technologies has developed a floating data center that it says can dramatically slash the cost of cooling servers. The company's data barge is being tested near San Francisco, and represents the latest chapter in a long-running effort to develop a water-based data center. Google kicked things off with a 2008 patent for a sea-going data center that would be powered and cooled by waves, conjuring visions of offshore data havens. Google never built it, but IDS soon launched its own effort to convert old Navy vessels into "data ships" before going bankrupt. Nautilus is using barges moored at piers, which allows it to use bay water in its cooling system,eliminating the need for CRAC units and chillers. The company says its offering may benefit from the growing focus on data centers' water use amid California's drought.