The Pea Green Boat

When Harry Tremaine is killed in the explosion of his fishing boat, suspicion falls on the man's son, who stands to inherit everything, but Wycliffe remains unconvinced. There's also a local developer who wants to build a marina on the quayside Tremaine owned; Tremaine's partner has been having an affair with his wife; and there is a mysterious recipient of £500 in cash from Tremaine on the first day of every month.