Is it true that prevail outside the international maritime borders no laws?

No, not the so. At sea there are many different legal provisions that are summarized under the heading of maritime law. Maritime law is the entirety of the lake and its use of applicable laws. It is characterized by numerous features, which are based mostly in the isolated situation at sea and in the absence of state sovereignty on the high seas. Can be distinguished private and public maritime law. Of particular importance are the international public law of the sea, which is the law of the sea, the maritime law in private law, public law, the maritime law, the flag of law and more.

I don't really remember that whole episode much but I am slightly familiar of it. Maybe it's true that there are some areas in the ocean that isn't owned by any country and there can be absolute freedom in whatever the people can do. But I doubt no one would want to get married there because first of all the marriage won't be valid anywhere else but in that specific part of the ocean. Maybe I just want to believe that there is such place but you know the things in The Simpsons are usually crazily made up...