I would love to see floating towns of people voluntarily living together, out in the water free from any nation's rules. They could structure whatever type of community system they wanted. If one wanted full-out communism, they could have it. If another wanted a floating Galt's Gulch, they could have that.
They could all freely trade with each other and with people on the mainlands.
The only three problems would be

• Hurricanes/Cyclones
• Rogue waves (those 300' monsters that come out of nowhere)
• Pirates

The first two could be countered with technology and ingenuity. Perhaps have eco-domes that you can close up, strap yourself into, and ride it out. Even if things get tossed around, you'll bob back up afterwards and keep chugging along.
The pirates, though...without your own formidable navy, you're sitting ducks.