The boat that takes tourists there is called 'The Scillonian'.
..I'll let myself out.
(I've heard "Scilly Isles" far more often than "Isles of Scilly", but I'm nowhere near local.)
A Ministry of Scilly Walks.
Not many people even in the UK know it exists though (I only do because my ex girlfriend grew up there)
Though... the more time goes on, the more I expect to hear "oh, they still broadcast the weather on TV? I thought they just did that during the war"... and by war, they're referring to the Gulf war... along with "Walkman/Discman? What's that?"
Well, I have an explanation that doesn't involve aliens: I didn't read the name of the island correctly. Good job from the conspiracy to hide itself very well, but next time I'll catch you anyways.