>>80908
The way I would want it is for there to be at least a small island just to have some solid ground to stand on, to have hotels and resorts to attract tourists, to act as a park or nature reserve to chill in, and most importantly to provide shallow water for companies to build sea platforms at a lower cost than in the deep ocean.
The sea and the surrounding sea platforms are where most of the population, housing, agriculture, business, and industry is going to be, the platforms are interconnected by bridges, zip lines, slides, underwater tubes and various other forms of transportation. There are different ways companies build these platforms, some of them float on the surface but are anchored to the seafloor, some of them are resting on long columns extending from the seafloor, some of them aren't even platforms but artificial islands made from rocks and sand dumped into the shallow parts of the sea. There will also be some long ones to protect the rest of the city from strong waves.
Besides buying space on a platform, there are various other places for people to be. Some people have their own houseboats, which they also use as transport to move around from place to place and as a shop to sell goods, some people live in large retired ships that were supposed to be sunken or dismantled but special companies renewed and repurposed them into sea-buildings for various purposes (cheap housing, commercial space, farmland, heavy industry, etc…), some companies even have enough money to build large high-tech floating complexes or seascrapers in the deeper parts.
When someone owns their own "land", they own it completely, they don't pay tax and they decide their own rules for everyone located in it, but the NAP (which is enforced by a privatized police, security and military) has to be followed everywhere.