> I see no reason why someone can't end up in Brittain just by accidentally falling in the north sea and maybe clinging to whatever floats around I would expec

> I see no reason why someone can't end up in Brittain just by accidentally falling in the north sea and maybe clinging to whatever floats around I would expect that even Paleolithic people could deliberately put together something better than that; e.g, a raft, kayak or coracle from wood bound with hide. Once you have that skill, "some adventurous people" would of course try to achieve a landing on that island on the horizon.