Google's secretive empire took a hit today, as the tech giant was ordered to move its "mystery barge" from its dock at Treasure Island in the San Francisco Bay.
The four-story barge is one of two such structures, and no one really knows what's inside. (Though speculation runs rampant.) Google has had controversies like this before, such as when it came under fire for buying cheap fuel from NASA for private planes, including one "light attack jet."
While Google assembles its apparent fleet, barge architecture is no mystery. Here are some other examples of marine structures that will float your boat.