Again, the claim "Great Britain has never formally recognized Sealand's independence, but as affirmed by several decisions by British courts and government agencies, Sealand enjoys a de facto sovereignty" isn't true. The United Kingdom recognized it as outside their territorial jurisdiction prior to their extension of territorial waters to 12 nautical miles. Since then it has been under UK jurisdiction. If there has been no official UK pronouncement to that effect (beyond the one concerning the extension of the territorial sea) with respect to Sealand, it is simply because the UK government and courts regard Bates as a kook and choose to ignore him.
And I could go on... -- SJK
There's a lot of precedent on the extension-of-waters front which favors Sealand. When the treaty was signed, this issue came up repeatedly. Otherwise, neighboring countries could claim the territory of others.
Sealand being of artificial construction is unique also, since it was constructed illegally by a third party (UK) during WW2, for a purpose other than land extension. Sealand existed and was a country long before the relevant UN treaties on artificial structures in the sea. Several promiment law professors have basically said Sealand's status as land is the same as reclaimed land in Holland or elsewhere. I can include hypertext links to these documents.
I'll include a summary of the legal issues in another edit of the article (and re-edit the HavenCo article to be a bit more factual; I just cut and pasted quickly to get something up) -- Ryan Lackey
How was the UK construction of it illegal?
Secondly, even if you are correct in stating Roughs Tower as being territory, that doesn't make Sealand a state. Merely claiming unoccupied territory is not sufficent to bring a new state into existence. At the very least it needs to comply with the Montevideo convention criteria, and likely needs to be recognized by other states as well.
And the extension of waters argument only works if Sealand is a state. -- SJK
The UN has repeatedly upheld the right of self determination of "dependent territory" non-self-governing people. If Pitcairn wanted to become independent, they would 1) have every right to by UN agreements 2) would be encouraged to do so by the UK (there was a white paper circulated by the UK to british dependent territories about ~2 years ago which asked them to do so, since the EU is now trying to force the UK to either give overseas territory British passports or make them independent (perhaps commonwealth, though). I was living on Anguilla, another british dependent territory, at the time, and it was a major issue.
Sealand's claims, regardless of validity, are much more complex than Hutt River, Republic of Texas, etc., even if only due to touching on admiralty/maritime law (which is very complex) and that the issue has now dragged out over nearly 60 years; the laws have actually changed several times in the interim.
There are perhaps 7 major points:
I'll make 1-2 paragraph wiki articles about each topic and then deep-link onto the legal site with original documents.