It may look like it's capsizing, but the FLIP (Floating Instrument Platform) is the only vessel out there that can operate both horizontally and vertically. It was designed to "flip" at sea so that scientists can better study the ocean. What I think is especially cool is that the insides of the ship (the crew quarters) were made in a way that you can get around regardless of what position the ship is in. I'd just hate to be anywhere near the bathroom when that thing flips. Check out the video post jump.
Although they only do it once, deep-sea oil platforms are also capable of flipping. The long cylindrical bases are hauled out to site floating horizontally, and once in location they fill one end with water until they float upright, albeit mostly submerged to reduce the effects of waves and swells. They don't go back again, but it might make this ship a little less unique (in that the technique is commonly used elsewhere.)