HMS Troutbridge sets sail with Phillips let loose on a new navigational aid.

Starring Leslie Phillips as the Sub-Lieutenant, Jon Pertwee as the Chief Petty Officer, Stephen Murray as the Commanding Officer, Richard Caldicot as Captain Povey, Heather Chasen as Wren Chasen, Tenniel Evans as the Admiral and Michael Bates as Mr Harris.

Scripted by Lawrie Wyman and George Evans.

Producer: Alastair Scott Johnston.

First broadcast on BBC Radio 2 in November 1975 : Series 15, Episode 2