Viewed this film online and though they were not in the 'prime' of their stardom (Richard Dix, Dolores Del Rio Chester Morris), they enacted their roles capably and highlighted the action with this movie which is an interesting remake of Submarine (1928).Spoiler Alert: Ace Navy diver, Jack Dorgan and his aide for many years, Robert Mason, are separated when Jack receives orders to relocate to San Diego as a diving instructor and Bob is named chief petty officer of a submarine. In San Diego, Jack is consoled when he realizes his dream of owning a house but soon becomes bored with his new lifestyle and decides to go out for a night on the town. At a dance hall, Jack meets Carmen, a beautiful taxi dancer. Jack is immediately infatuated with Carmen, who tells him a misleading hard-luck story. Jack believes Carmen's story and asks her to marry him. Before they can go on a honeymoon, however, Jack is sent away on a salvage job. Carmen becomes bored and soon returns to her job at the dance hall. One night, Bob, who is on shore leave, visits the dance hall and falls in love with Carmen. Carmen does not reveal her marriage, and she and Bob enjoy one another's company for the remainder of the time that Jack is away. When Jack returns home, he is incensed to find Bob in Carmen's arms and throws Bob out of his house. Back at sea, Bob's submarine collides with an old shipwreck and sinks. Several crew members manage to escape and they alert the Navy. When Jack is called in to rescue the stranded crew, he refuses to help because Bob is on board. Carmen is outraged at Jack's behavior and confronts him, explaining that Bob is not guilty of any wrongdoing. Jack realizes how foolish he has been and rushes to the submarine site, where the trapped men are close to asphyxiation. Attaching an air hose to the submarine, Jack saves Bob and the rest of the crew. After recuperating, Bob and Jack are sent to China, and Carmen returns to the dance hall.What is great about this movie is the interesting take on loyalty and friendship with the Dolores Del Rio character coming between them but she ultimately decides what is the 'right thing' to do and because of her actions---ends up alone and the guys re-start their friendship.