Three young boys discover a sunken sailing ship near their home in Odessa. Gleb, leader of the three, decides to raise the boat to use it for cruises, but he wants to do it his way, which is not the collective way of The Young Pioneers. He and his friends build a makeshift crane, but the mechanism fails. A sympathetic sea captain, using more scientific means, manages to raise the boat, but Gleb refuses to join the other kids in repairing the boat and continues his lone-ranger behavior. However, wiser guidance brings him to eat humble pie and he joins the others, and is made captain of the craft.