Watch Free Online HD Moviesjoy. In this episode, Josh Gates explores the remains of an American ship sunk by a Nazi U-boat during WWII. The quest takes a thrilling turn as he teams up with shark expert Tristan Guttridge, who introduces a groundbreaking approach: using sharks as underwater spies to uncover the wreck. This innovative strategy promises to shed new light on the shipwreck and the events surrounding its demise decades ago.