A widely respected deep-sea diver is approached by a ring of con artists who want him to be the front man for a phony scheme to recover gold from sunken ships. When he refuses, they send a sexy young woman to seduce his son, and then blackmail the father into going along with their scheme.
Practical Effects
Underwater photography was genuinely dangerous in 1920.
Acting
Bosworth's weathered face does the heavy lifting.

Director
Irvin Willat
Trivia, insights & behind the scenes
Hobart Bosworth was 56 and genuinely performed in pressurized diving gear that caused permanent hearing damage.
This was among the last major productions before Hollywood's self-censorship crackdown — note how freely sexuality functions as weaponry.