Newlyweds Tony Hudson (John Gregson) and young wife Jane (June Thorburn) are invited to join their industrialist friend Dudley Partridge (Cecil Parker), his absent-minded wife Valerie (Avice Landone) and a few friends on a battered old yacht for a trip to the French port of Dinard.
Although Jane suffers from chronic seasickness, she accepts and they go onboard the Turtle.
A lot of misadventures await them before they finally reach the harbour of Dinard. In France, they visit a casino and shortly afterwards become aware that one of their number, Harry (Australian Keith Michell in his feature film debut) has an ulterior motive.
Before long, the yacht is stranded mid-Channel in a dense fog.
Released in some markets as Plain Sailing.
Jacques B. Brunius
Sir Harold Brazier
Michael E. Briant