In 1943, during the height of World War II, Rip Crandall, a seasoned U.S. Navy Lieutenant and a passionate yachtsman in his civilian life, finds himself stationed in Townsville, Australia. His routine military duties take a surprising turn when he's assigned command of the USS Echo, a rare sailing ship within the Pacific Fleet. This vessel, unlike the modern warships around it, relies entirely on sails and traditional navigation, making it a unique and somewhat unusual part of the war effort.
The ship's only sailor experienced with sailing ships is the eager and ambitious Ensign Tommy Hanson (played by Ricky Nelson), a young officer who has a history with Crandall—most notably, he once competed against him in a yacht race, where a mistake cost Crandall a victory. Despite Crandall's initial reluctance and attempts to refuse this seemingly insignificant command, his former sailing buddy, Lieutenant commander Wilbur Vandewater (possibly a character referenced in the story), convinces him otherwise. Vandewater, aware of Crandall's less-than-stellar fitness report, warns him that refusing the assignment could mean no future commands.
Crandall, feeling the pressure, tries to get closer to his crew—especially Hanson—by taking him out for drinks. This bonding effort aims to foster camaraderie but also subtly underscores the emotional strain of war. As they prepare to leave, the USS Echo sets out, barely escaping the harbor in a storm with many obstacles in its path. Amid this chaos, the ship inadvertently sails into a minefield near Port Moresby, New Guinea, adding danger to their mission.
Crandall's primary task is to train a new crew member to deliver a coastwatcher named Patterson (Patricia Driscoll) to a remote location only a vessel with a shallow draft can access. Instead of following instructions, Crandall questions the competence of the replacement officer, perceiving him as stiff and inexperienced, and decides to take the ship herself to fulfill the mission. Under his command, the USS Echo makes a daring crossing disguised as a native trading vessel, a risky move that exposes them to Japanese patrol planes.
Unfortunately, their cover is blown when a Japanese reconnaissance aircraft photographs the ship. During their covert operation, the crew is spotted, and aboard the ship, Japanese forces boards the USS Echo, capturing Crandall and most of the crew. Once ashore, the enemy forces return, leaving the crew with the daunting task of reclaiming their vessel. Rallying his men, Crandall leads a daring effort to retake the ship, but he sustains injuries in the process.
Amidst the chaos, Hanson faces a critical decision: whether to risk broadcasting a warning about the Japanese fleet—which could reveal their position and jeopardize the entire operation—or stay silent. He chooses to send the warning, understanding the importance of alerting allied forces. The Japanese open fire on the vessel, destroying the USS Echo in a final act of defiance.
Despite the loss of their ship, the crew survives and is rescued. Their critical contribution to the Battle of the Bismarck Sea earns Crandall a well-deserved command of a modern destroyer, symbolizing his bravery and leadership. Meanwhile, Hanson is awarded command of a sub chaser, marking a promising advancement in his naval career.
This story highlights themes of courage, leadership, and the unconventional roles that can define heroism during wartime, showcasing how even a sailing ship can play a pivotal part in a larger conflict.