Longitude

Michael Gambon

John Harrison

Jeremy Irons

Rupert Gould

Gemma Jones

Elizabeth Harrison

Anna Chancellor

Muriel Gould

Emma Kay

Laura Gurney

Barbara Leigh-Hunt

Dodo Gould

Peter-Hugo Daly

John Jefferies

Alec McCowen

Sir Frank Dyson

Kevin Hudson

Lieutenant (uncredited)

T. P. McKenna

Edmund Burke

Peter Cartwright

Army Doctor

Alfred Burke

Rear Admiral

Jonathan Coy

Admiral Clowdisley

Christopher Hodsol

Captain Ainsley

Samuel West

Nevil Maskelyne

Clare Lawrence-Moody

Staff Nurse

Ian McNeice

Dr. Bliss

Clare McCarron

Nurse

Ian Hart

William Harrison

John Nettleton

Minister for the Navy

Bill Nighy

Lord Sandwich

Brian Cox

Lord Morton

Nigel Davenport

Sir Charles Pelham

Liam Jennings

Young William