 Richard AttenboroughDripper Daniels | Dripper Daniels |
 James DonaldLt. Richard Jennings, No. 1 | Lt. Richard Jennings, No. 1 |
 Sonny TuftsYank Flanagan | Yank Flanagan |
 Trevor HowardLt. Cmdr Hugh Alginon Fraser | Lt. Cmdr Hugh Alginon Fraser |
 Bernard LeeA.S. 'Stripey' Wood | A.S. 'Stripey' Wood |
 Dora BryanGlad Flanagan | Glad Flanagan |
 Hugh WilliamsCaptain David G. Wilson | Captain David G. Wilson |
 Robin BaileyLt. Michael Grant, Pilot | Lt. Michael Grant, Pilot |
 Meredith EdwardsJones | Jones |
 John ForrestAppleby the Captain's Steward | Appleby the Captain's Steward |
 Patric DoonanPetty Officer Martin | Petty Officer Martin |
 Sidney JamesNed Hardy, Landlord Golden Bull | Ned Hardy, Landlord Golden Bull |
| HHarold SiddonsAdm. Bartlett | Adm. Bartlett |
 William RussellCrewman | Crewman |
 Joan RiceJune Mallory, WRNS cypher officer | June Mallory, WRNS cypher officer |
| PPeter BathurstCommander C.E. Spencer | Commander C.E. Spencer |
 Charles Lloyd PackCaptain R. G. Bates (Board of Inquiry) | Captain R. G. Bates (Board of Inquiry) |
| CChris AdcockCrewman (uncredited) | Crewman (uncredited) |
 Tim TurnerCrewman (uncredited) | Crewman (uncredited) |
| GGeorge SpenceMan in Pub (uncredited) | Man in Pub (uncredited) |
