When Fred Carpenter suggests to his wife, Sally, that they should take a boating holiday on the Norfolk Broads, she is filled with trepidation. Nevertheless she summons her courage and they and their bull-terrier Bill set off, with Fred at the helm of Dogfish Three. Sally's misgivings are soon justified, as a series of disasters – human, nautical and canine – threaten to ruin their holiday. Then everything changes as they make friends with the boating fraternity and encounter the remarkable 15-year-old Rosie, whose family history stirs their curiosity and sympathy. As a result, Fred and Sally decide to support Rosie's efforts to better herself – and are rewarded when she finds love and happiness.