Original sentence: Caisteal Calbhaigh is on a rocky islet in Loch Boisdale (the sea loch from which the village takes its name).It is accessible only by boat, but visible from the vehicle ferry.It was here that the ship SS Politician ran aground with its cargo of whisky in 1941.The island contains a lighthouse and the ruins of an old castle.The more southerly island is situated in the Sound of Eriskay.The second island is located off the mouth of Lochboisdale about four miles north to the north.Two small, uninhabited Islands, both named Calvay (Gaelic Calbhaigh)), lie off the coast of South Uist in the Outer Hebrides
Edited sentence: A second island of the same name is located off the mouth of Loch Boisdale off the coast of South Uist about four miles to the north.Calvay (), is an uninhabited island situated in the Sound of Eriskay in the Outer Hebrides.It was here that the ship SS Politician ran aground with a cargo of whisky in 1941 and inadvertently provided the inspiration for Compton MacKenzie's 1947 novel Whiskey Galore.This island contains a lighthouse and the ruins of an old castle called Castle Calvay/Caisteal Calbhaigh which is visible from the vehicle ferry at the entrance to the loch