A poor but brilliant inventor sets out to make his fortune by discovering buried treasure, with the aid of a special inverted periscope through which he can view the ocean floor.
| Actor | Role |
|---|---|
 Lillian CookPrologue | Prologue |
 Chester BarnettJohn Fulton | John Fulton |
 Barbara TennantDorothy Morgan | Dorothy Morgan |
 Eric MayneEarl of Linwood | Earl of Linwood |
| FFred RadcliffePrologue | Prologue |
| EE. HudsonPrologue | Prologue |
| LLindsay J. HallCaptain Bob | Captain Bob |
| CCharles HartleyJoe Lee | Joe Lee |
| EEdith ConwayNancy | Nancy |
| NNellie SlatteryParker | Parker |
| EEdward ButlerMurphy | Murphy |
| GGustave FischerAn officer of the 'Condor' | An officer of the 'Condor' |