John Harrison

Michael Gambon

Rupert Gould

Jeremy Irons

William Harrison (Adult)

Ian Hart

John Campbell

Andrew Scott

Muriel Gould

Anna Chancellor

Nevil Maskelyne

Samuel West

Admiral Cloudisley

Jonathan Coy

Alec McCowen

Lord Sandwich

Bill Nighy

Elizabeth Harrison

Gemma Jones

Sir Edmund Halley

John Wood

Sir Kenhelm Digby

Stephen Fry

Brian Cox

Grace

Lucy Akhurst

Dodo Gould

Barbara Leigh-Hunt

Lord Morton

Brian Cox

King George

Nicholas Rowe

George Graham

Peter Vaughan

Dr. Bliss

Ian McNeice

Army Doctor

Peter Cartwright

Capt. Ainsley

Christopher Hodsol

William Harrison (Young)

Liam Jennings

Rebecca Clay

Waddington

Michael Cochrane

Sir Charles Pelham

Nigel Davenport

Christopher Irwin

Tim McInnerny

Roger Wills

Trevor Cooper

Capt. Proctor

John Standing

Sarah Badel

James Bradshaw

John Jefferies

Peter Hugo Daly

Capt. Bourke

Daragh O'Malley

Lt. Draper

Cliff Parisi

Robert Demeger

Phil Dix

Lt. Seward

Charles Edwards

Halley's Secretary

Tobias Menzies

Frank Finlay

Capt. Lindsay

Pip Torrens

Clive Francis

Alfred Burke

Edmund Burke

T. P. McKenna

Charles Gray

Sasha Hails

Mr. Greene

John Normington

Capt. Man

Roger Lloyd Pack

Surgeon

Peter Penry-Jones

Director

Charles Sturridge