Rupert Gould
Muriel Gould
Laura Gurney
Nevil Maskelyne
Dr. Bliss
John Harrison
William Harrison
Lord Sandwich
Lord Morton
Dodo Gould (as Barbara Leigh Hunt)
Elizabeth Harrison
John Jefferies (as Peter Hugo Daly)
BBC Producer
Captain Campbell
Surgeon
Lt. Seward
Captain Digges
Learmouth
Lt. Williams
Sir Frank Dyson
Commodore Forrest
Inn Landlord
Captain Bourke (as Darragh O'Malley)
Lt. Bandelwine
Bosun
Marine (as Steven Morphew)
BBC Researcher
Christopher Irwin
Mr. Greene
Captain Lindsay
Governor
Amy
Doctor
Observatory Assistant
Young Assistant
Lady Curator
Grace Ingram
King George
Queen Charlotte
Dr. Demainbray
Callboy
Edmund Burke
Society Lady
Lt. Bertie
Jos Killick
Rear Admiral
Army Doctor
Waddington
Roger Wills
Adm. Sir Cloudsley Shovell
Sir Charles Pelham
Observatory Porter
Adm. Wagner
Sir Kenelm Digby
Adm. Balchen
Capt. Ainsley
Estate Manager
Young William Harrison
Dyson's Secretary
Staff Nurse (as Clare Moody)
Minister for the Navy
Lt. Draper
Dr. Bradley
John Campbell
Lt. Knorvler
James Harrison
Capt. Proctor
Whiston
Arthur Mason
George Graham
Ditton
Sir Edmund Halley
Clock Box Carrier (uncredited)
Carpenter (uncredited)
Portuguese Child (uncredited)
Naval Captain (uncredited)
WW1 Soldier (uncredited)
Lieutenant (uncredited)
Sailor (uncredited)
Blonde Girl (uncredited)
Courtesan (uncredited)
Narrator (uncredited)
Capt. Man (uncredited)
Lt. Chester (uncredited)
Nurse (uncredited)
Halley's Secretary (uncredited)
Marine (uncredited)
Cecil Gould (uncredited)