At Port Coral in the South Seas, German merchant Sam Miller is told by fisherman Frank Williams that there is a swimming pool full of gold and gems on Temple Island. Miller tells Williams that he discovered the treasure twelve years earlier, and convinced Princess Tahia, the local leader, to forbid white men from exploring the island. After strangling Williams, Miller hides to avoid seeing Tahia, who is angry with the merchant's bad influence on her brother Tamara. Meanwhile, shark fisherman Kaloe is upset to learn from his friend Orano that Tahia has refused to grant him fishing rights to the reefs around Temple Island. Kaloe then meets Tahia, but not knowing who she is, complains to her about "the old tub of lard" who rules Temple Island. Later, Orano arranges for Kaloe to meet with Tahia, but the upset Tahia has Orano's mother Blossom impersonate her. Upon learning the truth, Kaloe romances Tahia, but she banishes him from the island because she believes that he is only interested in her for the island's fishing rights. After borrowing $1,500 from Wong, a lawyer and jack-of-all-trades, for supplies and a new fishing boat, Kaloe schemes with Orano to get back into Tahia's good graces. Their plans work, and the smitten princess takes the fisherman on a tour of her island, which includes the jewel-laden swimming pool. Kaloe warns Tahia that while he is uninterested in the treasure, Miller may not be so disinclined. Later, the merchant goes to Temple Island, where he saves Tahia from the unwanted advances of Erik, his Irish partner, then proposes marriage. The princess refuses him, and, in turn, rushes into the arms of Kaloe. Later, Miller allows Tamara to use the land deed to Temple Island as gambling collateral, but Kaloe forces his way into the poker game and wins back the deed. On the day Tahia is to announce her engagement to Kaloe, Miller arrives on Temple Island with the dead body of Tamara. As his knife was used to commit the murder, Kaloe is falsely accused of the killing and placed in a lions' den. That night, however, he is rescued by Orano, then goes to Wong for legal advice. They, along with Tahia, trick Chris, one of Miller's hoods, into confessing to the crime and implicating his boss. Learning that his true nature has been exposed, Miller and his heavily armed men head to Temple Island to forcibly take the jewels from the sacred pool. Their use of dynamite to empty the pool, however, sets off an earthquake which kills them and destroys much of the island. With Miller dead and the island deed safely in her name, Tahia happily reunites with Kaloe, as a beaming Orano looks on.