>Are there are any structures for large numbers of people to live on the ocean that are actually.... practical? Oil drilling platforms have refined the concept

>Are there are any structures for large numbers of people to live on the ocean that are actually.... practical? Oil drilling platforms have refined the concept pretty well. 1. Replace the drilling stuff with a casino to make money. 2. Park it somewhere nobody cares about. 3. "Import" your groceries. 4. ????? 5. Live peaceably in your utopia.