Ships disappear on route across the Arctic Sea, and a special submarine is sent to investigate.
| Actor | Role |
|---|---|
 Arthur FranzRichard "Reef" Holloway | Richard "Reef" Holloway |
 Dick ForanDan Wendover | Dan Wendover |
 Brett HalseyCarl Neilson Jr. | Carl Neilson Jr. |
 Tom ConwayIan Hunt | Ian Hunt |
 Paul DubovDavid Milburn | David Milburn |
 Bob Steele"Grif" Griffin | "Grif" Griffin |
 Victor VarconiClifford Kent | Clifford Kent |
 Joi LansingJulie | Julie |
 Selmer JacksonAdmiral Terhune | Admiral Terhune |
 Jack MulhallJustin Murdock | Justin Murdock |
 Jean MoorheadHelen Milburn | Helen Milburn |
| RRichard TylerFrogman Carney | Frogman Carney |
 Kenneth BeckerFrogman Powell | Frogman Powell |
 Sid MeltonChester Tuttle | Chester Tuttle |
| FFrank WatkinsWatkins | Watkins |
| PPat MichaelsNarrator | Narrator |
| JJohn HilliardSaucer Voice (voice) | Saucer Voice (voice) |
 Edmund CobbPasserby (uncredited) | Passerby (uncredited) |
 Frank LackteenPasserby (uncredited) | Passerby (uncredited) |