A crack team of Italian naval divers plan to attach high explosives to the hulls of Royal navy warships anchored in Gibraltar harbour.
| Actor | Role |
|---|---|
 Eleonora Rossi DragoMarion | Marion |
 Pierre CressoySilvano | Silvano |
| CCarlo BelliniNot listed | Not listed |
 Tino CarraroCommander | Commander |
| GGiovanni De FazioNot listed | Not listed |
 Charles FawcettNot listed | Not listed |
 Riccardo GarroneNot listed | Not listed |
 Paul MüllerForeign agent | Foreign agent |
 Rio NobileNot listed | Not listed |
| CColombo PamolliNot listed | Not listed |
 Paolo PanelliNot listed | Not listed |
 Mimmo PoliNot listed | Not listed |
| GGiorgio SpaccarelliNot listed | Not listed |
| GGiovanni TadiniNot listed | Not listed |
| TTsao Hong TcheNot listed | Not listed |
 Mario Ferrari(Voice dubbing for Pierre Cressoy) | (Voice dubbing for Pierre Cressoy) |
| AAdriana de Roberto(Voice dubbing for Eleonora Rossi Drago) | (Voice dubbing for Eleonora Rossi Drago) |