Seasteading

The aims of The Seasteading Institute are to create permanent dwellings on the oceans, outside of any national boundaries.

http://seasteading.org/

This is much like other projects that want to create floating cities outside any jurisdictions that will be a haven for 'civil liberties'.

The problem is that only the rich will be able to afford them, at least initially. If the projects are successful then the price might decrease.

Also, there is nothing to stop militaries from any number of countries interfering.