TADEAS: Basically, floating Peenemünde :)
"There are a lot of potential benefits from going to sea. But the most immediate benefit for Elon Musk is that
launching from international waters puts SpaceX beyond the reach of pesky U.S. regulators. Elon has made no secret that he has little time to waste on government compliance. By fielding floating spaceports, and then sending those spaceports out to international waters, a lot of potentially irksome and time-wasting regulatory problems disappear. And if parts of SpaceX’s navy starts operating under flags of convenience, everything from U.S. taxes,
basic American labor standards, worker safety and environmental compliance requirements can, by and large, just go away."