When the British Parliament creates an award of £20,000 to whoever can come up with a solution for determining longitude at sea, a carpenter-turned-clockmaker, John Harrison, begins his experiments to build an accurate timepiece unaffected by sea travel. His main obstacles are lack of money, a judgment Board convinced that the answer lies in astronomy and not clocks, and the mechanics of the clock itself.
Ian Hart
William Harrison
Michael Gambon
John Harrison
Jonathan Coy
Adm. Sir Clowdisley Shovell
Jeremy Irons
Rupert Gould
Peter Cartwright
Army Doctor
Gemma Jones
Elizabeth Harrison
Anna Chancellor
Muriel Gould
Stephen Fry
Sir Kenhelm Digby
Samuel West
Nevil Maskelyne
Ian McNeice
Dr. Bliss
Bill Nighy
Lord Sandwich
Brian Cox
Lord Morton
Barbara Leigh-Hunt
Dodo Gould
Peter-Hugo Daly
John Jefferies
Gary Waldhorn
Commodore Forrest
Tim McInnerny
Christopher Irwin
Hugh Simon
Doctor
Alfred Burke
Rear Admiral
Michael Cochrane
Waddington
Nigel Davenport
Sir Charles Pelham
Roger Lloyd Pack
Capt. Man
Tobias Menzies
Halley's Secretary (uncredited)