Oil company employee Joe Beck [Robert Lowery] is stationed deep in the Honduran jungle when the news from Texas arrives: his grandfather has died, leaving him a substantial inheritance of $200,000. In a nearby port, he meets with the testament executor to collect the news, and the moment he’s ready to head back into the jungle, a suspicious man hired by the attorney tries to knock him out. Joe fights back, kills the intruder, and makes his way to a ship that will carry him away with his new fortune.
On the vessel, the Merman, a steady hand named Dawson [Alec Craig] has helped Joe before, and the two form a wary alliance. A small shipboard world gathers around them: Captain Saul [William Edmunds], a firm, capable man at the helm, and his first mate Buck Harris [Victor Kilian], a loyal but watchful presence. Also aboard is Nita Paxton [Phyllis Brooks], a sultry cabaret performer who immediately draws Joe’s interest and curiosity. The atmosphere is crowded with murmurs and rumors, and Joe senses that danger may follow him even far from home.
Before the ship reaches its first port, tragedy strikes: Dawson is murdered. Joe acts quickly to prevent blame from falling on him, disposing of the body by feeding it to the fish and thereby keeping the mystery off his own trail. The ship’s mood shifts from romance and routine to a tense, dangerous game as Joe and Nita drift toward a shared attraction while new suspicions swirl around them. When they go ashore in Los Altos, the two begin to romance in earnest, unaware that the danger has only begun to close in.
Back on the Merman, the situation intensifies. The testament executor’s representative—an uneasy confrontation with [Charles Arnt]—appears with a man who poses as Joe Beck, aiming to seize the inheritance. Joe quickly restores control of the situation by handling the impostor and the paper trail remains in jeopardy. Nita, meanwhile, reveals a startling truth: Dawson was an undercover agent for an insurance company, and his mission hinted at possible insurance fraud involving the ship’s captain and crew. She had been trying to carry on his work after his disappearance, keeping the pressure on to uncover the truth.
Despite the peril, Bergstrom’s plan to secure the inheritance still lingers in the background as a possible motive for betrayal. The ship’s course shifts again when a mid-ocean disaster strikes and the ship rams a rocky coast. In the chaos, Joe awakens after being knocked unconscious, and Nita breaks into his cabin with an axe to free him. The few survivors—Joe, Nita, Bergstrom, and the impostor—scramble for safety as rescue planes circle the area.
Days later, Joe travels to Galveston, Texas, to retrieve the identification papers he sent ahead, only to learn that Nita has already been there and retrieved them for herself. He tracks her down and discovers her with Bergstrom and the impostor, who threaten to kill her unless the papers are handed over. Joe climbs into the apartment through a window and, acting in self-defense, shoots the impostor as Bergstrom reaches for the papers. Bergstrom phones in a claim to the police, attempting to have Joe arrested for the murder, but Joe’s control of the situation allows him to overpower Bergstrom instead. When the police arrive, Bergstrom is taken into custody, and Joe and Nita share a kiss, choosing each other as the true anchors of their uncertain lives.
In the end, the dangers of greed, deceit, and the treacherous lure of easy money are laid bare, but the bond between Joe Beck and Nita Paxton endures. The ocean’s shadowy perils threaten them, yet their trust and resolve push them toward a future where love and honesty stand as the brighter reward after a voyage marked by peril and pursuit.
