Michael Gambon

as John Harrison

Jeremy Irons

as Rupert Gould

Ian Hart

as William Harrison (Adult)

Andrew Scott

as John Campbell

Bill Nighy

as Lord Sandwich

Gemma Jones

as Elizabeth Harrison

John Wood

as Sir Edmund Halley

Anna Chancellor

as Muriel Gould

Brian Cox

as Lord Morton

Samuel West

as Nevil Maskelyne

Ian McNeice

as Dr. Bliss

Jonathan Coy

as Adm. Sir Cloudsley Shovell

Christopher Hodsol

as Capt. Ainsley

Liam Jennings

as William Harrison (Young)

Peter Vaughan

as George Graham

Nigel Davenport

as Sir Charles Pelham

Tim McInnerny

as Christopher Irwin

John Standing

as Capt. Proctor

Peter Cartwright

as Army Doctor

Stephen Fry

as Sir Kenelm Digby

Daragh O'Malley

as Capt. Bourke

Cliff Parisi

as Lt. Draper

Michael Cochrane

as Waddington, Gould's solicitor

Tobias Menzies

as Halley's Secretary

Charles Edwards

as Lt. Seward

Pip Torrens

as Capt. Lindsay

T. P. McKenna

as Edmund Burke

Barbara Leigh-Hunt

as Dodo Gould

Peter-Hugo Daly

as John Jefferies

John Normington

as Mr. Greene

Nicholas Rowe

as King George

Roger Lloyd Pack

as Capt. Man

Trevor Cooper

as Roger Wills

Lucy Akhurst

as Grace Ingram

Peter Penry-Jones

as Surgeon

Mark Tandy

as Whiston

Heike Makatsch

as Queen Charlotte

William Thomas

as Arthur Mason