A barge afloat in the San Francisco bay just off the shore from Treasure Island is home to something the locals refer to simply as the secret project. The mysterious four-story tall building that sits on top of the barge was built from shipping containers and if CNET’s investigative team is correct, it could be a massive floating data center owned by Google.

Maintaining a data center requires a large amount of cooling to keep the servers at safe operating temperatures. By building a data center on a barge, the servers could easily and cheaply be cooled by the surrounding water. Saltwater could potentially be problematic but it’s not an insurmountable endeavor.

What’s more, building data centers inside of shipping containers isn’t out of the norm. Companies like Dell, HP, Microsoft and Sun Microsystems have been doing so for a while now simply because such setups are easy to deploy.

Perhaps the most damning evidence is the fact that Google was granted a patent for a water-based data center back in 2009. Specifically, the patent covered a floating platform-mounted data center with a sea-based electrical generator and sea-water cooling units. That sounds like a pretty solid fit of what’s likely going on in the San Francisco bay.

The publication dug up a wealth of evidence which pointed towards the search giant as the entity behind the project but for the sake of brevity, I won’t go into everything they found. If you’re interested in learning more, be sure to pop over and check out their article.