When Basil Beauchamp, alias Dr Dare (Simon Dee), TV's heartthrob doctor is admitted to St. Swithin's Hospital, it leads to an unusual course of therapy. Cantankerous Head Surgeon Sir Lancelot Spratt (James Robertson Justice), prescribes a cruise aboard a ship, skippered by his brother George (Robert Morley). Meanwhile, Dr Burke (Leslie Phillips) must arrange a rushed marriage of convenience in order to land a top medical job in America. But in a crazy course of circumstances, he ends up as a stowaway on board the very same ship when he follows his intended, Ophelia, on a Mediterranean modelling trip. Needless to say chaos rules as Dr Burke vainly attempts to avoid detection. A task made all the more difficult when he has to face passengers such as Harry Seacombe, a larger than life pools winner and an outrageous mum looking for a love match for her daughter - a striptease artiste!