Sealand was what gave me the idea of a barge in international waters being a gun mecca.
Why not just invade Sealand?
See that big bastard Oerlikon-looking thingy, sitting on top? That's why.
I live really near to Sealand, actually. You can see it quite clearly from Felixstowe seashore. It's a shame "His Royal Highness" is such a nutter -- I'd love to see what it's like over there. He even warns off any small fishing boats, who sail too close to the tower.
And yep, every so often, somebody gets the idea that it'd be a great wheeze to invade Sealand... Only they tend to underestimate quite how seriously His Royal Fruitloop takes his principality. He came back once in a helicopter, tooled-up like something from a Frederick Forsyth novel and took the whole lot back by force. Even the Royal Navy tend to give Sealand a wide berth...