Submarine X-1

Cmdr. Richard Bolton, RNVR

Lt. Davies R.N.V.R

Sub-Lt. Pennington, RN

Leading Seaman Quentin

CPO Barquist X 3

Lt. Robert Talbot Gogan R.N.R.

Sub-Lt. Keith Willis, RNVR

CPO Boker Knowles

CPO Norman Kennedy

Leading Seaman X-2

Leading Seaman X-1

Capt. Erlich of the 'Lindendorf'

Vice Admiral Redmayne (uncredited)

Sub. Lt. X-3

WRNS Officer (uncredited)

Cmdr. Steiner (uncredited)

German Lieutenant (uncredited)

Naval Doctor (uncredited)

Sub-Lieutenant on X-1 (uncredited)

Seaman in Self-defence Demonstration (uncredited)

Redmayne's Flag Officer (uncredited)

Captain in Redmayne's Office (uncredited)