"... and coming back up with bottles of whisky which they would then hide from the customs."
The ship was the SS Politician. The islanders were from Eriskay, in the outer Hebrides. There were 100s of cases of whisky recovered and hidden from the authorities during WWII.
The link goes to a story about an auction of a couple of the bottles. There was a book — "Whisky Galore" (alternate title "Tight Little Island" — and then a movie by the same name that was made in 1949.
"For a true islander, life without [whisky] is not worth living."