 James CaanCmdr. Richard Bolton, RNVR | Cmdr. Richard Bolton, RNVR |
 David SumnerLt. Davies R.N.V.R | Lt. Davies R.N.V.R |
 Norman BowlerSub-Lt. Pennington, RN | Sub-Lt. Pennington, RN |
 Paul YoungLeading Seaman Quentin | Leading Seaman Quentin |
 Brian GrellisCPO Barquist X 3 | CPO Barquist X 3 |
 William DysartLt. Robert Talbot Gogan R.N.R. | Lt. Robert Talbot Gogan R.N.R. |
 John KellandSub-Lt. Keith Willis, RNVR | Sub-Lt. Keith Willis, RNVR |
 Kenneth FarringtonCPO Boker Knowles | CPO Boker Knowles |
 Carl RiggCPO Norman Kennedy | CPO Norman Kennedy |
| SSteve KirbyLeading Seaman X-2 | Leading Seaman X-2 |
 Nick TateLeading Seaman X-1 | Leading Seaman X-1 |
 George PravdaCapt. Erlich of the 'Lindendorf' | Capt. Erlich of the 'Lindendorf' |
 Rupert DaviesVice Admiral Redmayne (uncredited) | Vice Admiral Redmayne (uncredited) |
| KKeith AlexanderSub. Lt. X-3 | Sub. Lt. X-3 |
| DDiana BeeversWRNS Officer (uncredited) | WRNS Officer (uncredited) |
 Paul HansardCmdr. Steiner (uncredited) | Cmdr. Steiner (uncredited) |
| LLuke HansonGerman Lieutenant (uncredited) | German Lieutenant (uncredited) |
| DDesmond JordanNaval Doctor (uncredited) | Naval Doctor (uncredited) |
| DDennis MayersSub-Lieutenant on X-1 (uncredited) | Sub-Lieutenant on X-1 (uncredited) |
| DDoug RobinsonSeaman in Self-defence Demonstration (uncredited) | Seaman in Self-defence Demonstration (uncredited) |
 George RoubicekRedmayne's Flag Officer (uncredited) | Redmayne's Flag Officer (uncredited) |
| RRichard SteeleCaptain in Redmayne's Office (uncredited) | Captain in Redmayne's Office (uncredited) |
