It's a case of better the devil you know, when a temporary new Captain arrives on board HMS Troutbridge.
Jon Pertwee as the Chief Petty Officer
Leslie Phillips as the Sub-Lieutenant
Stephen Murray as the Number One
Ronnie Barker as Able Seaman Johnson
Richard Caldicot as Captain Povey
Heather Chasen as Mrs Povey
Michael Bates as the Laundry Manager
Tenniel Evans as the Clerk.