The Strangest Ship in the World

The Office of Naval Research owns a very strange piece of oceanographic equipment. It’s called the Floating Instrument Platform (FLIP) and isn’t even really a ship. It’s actually a huge specialized buoy, and the most interesting thing about it is….it really flips. FLIP is 355 feet long, with small quarters at the front and a long hollow ballast at the end. When the tanks are filled with air, FLIP floats in its horizontal position. When they’re filled with seawater, the lower 300 feet of FLIP sinks under the water and the lighter end rises. When flipped, most of the buoyancy for the platform is provided by water at depths below the influence of surface waves, making FLIP a stable platform, mostly immune to wave action. At the end of a mission, compressed air is pumped into the ballast tanks in the flooded section and the vessel returns to its horizontal position so it can be towed to a new location. During the flip, everyone stands on the outside decks. As the platform flips, the deck slowly becomes the bulkhead and the bulkhead becomes the deck. Most rooms on FLIP have two doors — one to use when horizontal, the other when FLIP is vertical. Some of FLIP's furnishings are built so they can rotate to a new position as the structure flips, while other equipment must be unbolted and moved. In the galley there are two tables and in the bathroom two sinks, so one is always in the correct position. The entire flip operation takes 28 minutes. When FLIP stands vertically, it rises more than five stories into the air. FLIP is designed to study wave height, acoustic signals, water temperature and density, and for the collection of meteorological data.