Characters played by John Mills
Lieut. Commander Armstrong
Characters played by Nigel Patrick
Lieut. Manson
Characters played by Peter Hammond
Sub Lieut. Oakley
Characters played by Andrew Crawford
Sub Lieut. (E) J. McFee
Characters played by Michael Brennan
C.P.O. Barlow
Characters played by George Cole
E.R.A. Marks
Characters played by Victor Maddern
Leading Telegraphist Hillbrook
Characters played by Roddy McMillan
Leading Seaman Andrews
Characters played by Frank Coburn
Leading Seaman Brough
Characters played by Jack Stewart
Leading Seaman Kelly
Characters played by James Hayter
Able Seaman Higgins
Characters played by Wylie Watson
Able Seaman Nobby Clarke
Characters played by Richard Attenborough
Stoker Snipe
Characters played by George Thorpe
Capt. Fenton
Characters played by Bernard Lee
Commander Gates
Characters played by Kenneth More
Lieut. Commander James
Characters played by Alastair Hunter
Capt. Jenner
Characters played by Helen Cherry
Helen Armstong
Characters played by Lana Morris
Rose Snipe
Characters played by Zena Marshall
The Wren
Characters played by Arthur Sandifer
(uncredited)