Brian - I don't think JP saw your questions?
I'll have ago at 'refuting' the logic of his 'explanation'.
1) He seems to accept that they were visual with the coast - good. One foot on board.
2) Unlike the other notable 'mis-ident' around there (the Loganair crash on Islay) their route did NOT require overflight of the landmass.
Thus logic surely suggests that WHICHEVER coastal feature they had seen, it would have shown where the coast was, behind which lies land?