I have followed any news about Sealand for a very long time. I also remember the failed attempt of hosting on it.
Here is a great outline;
I can’t imagine the technical issues of running a datacenter seven miles off the coast on cement pontoons tweety five off the ocean. Never mind keeping it powered up, connectivity would be a nightmare. Fiber? Yea I guess so, good luck with that. Satellite, better but expensive. Microwave is a good option, but anyone you pick has to go somewhere and that is the main problem. You can start your own nation but whats the use if no one wants to talk to you.