In 1875 Argentina, after killing a man, a gaucho is sentenced to harsh army duty but he deserts the army and becomes a bandit leader.

Mike and Tony Petrakis are a Greek father and son team who dive for sponges off the coast of Florida. After they are robbed by crooks, Arnold and the Rhys brothers, Mike decides to take his men to the dangerous 12-mile reef to dive for more sponges. Mike suffers a fatal accident when he falls from the reef leaving Tony to carry on the business. But now he has a companion, Gwyneth Rhys.

An aging Texas cattle man who has outlived his time swings into action when outlaws kidnap his grandson.