The current set of countries are protective of their oligopoly.<p>Generally, some nation will come and take it from you. Wolf Hilbertz developed an technique to electrically accrete limestone out of sea water and was using it to build a micronation, but it was almost certain that it would be seized by Mauritius when it broke surface.<p><a href="http://en.wikipedia.org/wiki/Saya_de_Malha_Bank#Artificial_island_project" rel="nofollow">http://en.wikipedia.org/wiki/Saya_de_Malha_Bank#Artificial_i...</a>