Lights on the River
Lights on the River is a 1954 Soviet children's film directed by Viktor Eisymont. A screen version of the novel of the same name by Nikolai Dubov.
Schoolboy from Kiev came on vacation to his uncle, a working buoy-driver on the Dnieper. Not at once, but he made friends with the local guys, and even helped his uncle to prevent the ship from crashing.