I was born in _arch, btw.

Yes it doesn’t exist, but the idea that it could exist and be unknown to an American tourist is not terrifically remote. Sorry if I wasn’t clear enough.

I make no claims for the base knowledge of any of my countrymen - they will make a fool of me if I try. But the distance between ~Donaghadee in N.I. and Portpatrick in Scotland is roughly the same between Dover and Calais.

Not knowing the geographic or hydrological factors of either area, it doesn’t seem to me to be much more impossible a feat than the chunnel was.

You live in a world with the chunnel. The odds that a similar passage between islands formerly of the same empire is not so remote.