A few small underwater habitats have popped up. They are populated mostly by the scientists that do their research from them and, for the most part, are not tourist spots.
This project, which began with the goal of becoming it's own soveriegn country, is a complete success. With a 2050 census population of just over 100,000 people (mixed race) the floating country covers a respectable amount of surface area. Instead of growing in an upwards direction, the country has expanded downwards, as well as outwards. The depth of the country is one of the things that keeps Oceania well out to sea. (National boundaries is another.)
The developers of Oceania also keep the country on the move. They constantly move the location of the man-made island to avoid ugly weather patterns, as well as to take advantage of favorable weather patterns.
Deep-sea fishermen have alleged that Oceania also does some raping of resources when they move through a region. This can be proven by smaller catches following the presence of Oceania. Hey, those folks gotta eat too, neh?