Michael Gambon

Character: John Harrison

Jeremy Irons

Character: Rupert Gould

Ian Hart

Character: William Harrison (Adult)

Andrew Scott

Character: John Campbell

Bill Nighy

Character: Lord Sandwich

Gemma Jones

Character: Elizabeth Harrison

John Wood

Character: Sir Edmund Halley

Anna Chancellor

Character: Muriel Gould

Brian Cox

Character: Lord Morton

Samuel West

Character: Nevil Maskelyne

Ian McNeice

Character: Dr. Bliss

Jonathan Coy

Character: Adm. Sir Cloudsley Shovell

Christopher Hodsol

Character: Capt. Ainsley

Liam Jennings

Character: William Harrison (Young)

Peter Vaughan

Character: George Graham

Nigel Davenport

Character: Sir Charles Pelham

Tim McInnerny

Character: Christopher Irwin

John Standing

Character: Capt. Proctor

Peter Cartwright

Character: Army Doctor

Stephen Fry

Character: Sir Kenelm Digby

Daragh O'Malley

Character: Capt. Bourke

Cliff Parisi

Character: Lt. Draper

Michael Cochrane

Character: Waddington, Gould's solicitor

Tobias Menzies

Character: Halley's Secretary

Charles Edwards

Character: Lt. Seward

Pip Torrens

Character: Capt. Lindsay

T. P. McKenna

Character: Edmund Burke

Barbara Leigh-Hunt

Character: Dodo Gould

Peter-Hugo Daly

Character: John Jefferies

John Normington

Character: Mr. Greene

Nicholas Rowe

Character: King George

Roger Lloyd Pack

Character: Capt. Man

Trevor Cooper

Character: Roger Wills

Lucy Akhurst

Character: Grace Ingram

Peter Penry-Jones

Character: Surgeon

Mark Tandy

Character: Whiston

Heike Makatsch

Character: Queen Charlotte

William Thomas

Character: Arthur Mason