So they want to create

floating libertarian countries in international waters

They’ve been looking at configurations, it seems. Ship, barge or semi-submersible? No self-respecting libertarian, with billions to donate, would go for something as prosaic as a barge, would they? Give me Verne’s Nautilus, dammit!  But that’s just me.

Still in all, nitty gritty factors such as water and sewage treatment don’t seem to have been examined yet by these pie-in-the-sea utopians. Being libertarians, maybe they won’t treat the sewage… they are trying to avoid pesky regulations, after all. But they will have to think about water for drinking. Surely they don’t want everybody puking over the side with some sort of nasty enteric disease. Wouldn’t look good at all.