Monty Halls is back to his roots as a marine biologist studying whales and dolphins off the spectacular west coast of Ireland.
This time his mission is to track down basking sharks, true monsters of the deep which can grow up to 30 feet long. They appear off our shores every summer but we know remarkably little about these gentle giants and Monty is on constant lookout for their telltale fins. He is determined to tag as many as he can in the hope that scientists can eventually discover their migration routes.
Back on shore, his attempts at self-sufficiency are sabotaged by otters, who've learnt to raid lobster creels, and his faithful dog Reuben, who accidentally savages him on a winkle-picking expedition.