The Sunken Sailor - Patricia Moyes

Inspector Henry Tibbett and his wife, Emmy, are enjoying a holiday on a friend's yacht, lazily sailing from one little English sea-town to the next. It should all be delicious indolence... except that Tibbett can't stop thinking about death. Well, one death in particular. The death of a local sailor. And he really can't stop thinking about it when it starts looking as though the drowned sailor is somehow connected to the robbery at a nearby manor house.