1 plot. On a collective contract. Leningrad. General view of the building of the Baltic Shipping Company. Marine vessel "Valery Kuibyshev" and other vessels in the port. One of the heads of the shipping company gives an interview (sinhr.). Sailors in the engine room of the ship at work with instruments. Loading works in the port. The main entrance to the territory of the Leningrad seaport. 2 plot. The ships are led by Orion. Sea vessel "Pakhom Makarenko" and other vessels in the port. Scientists work with instruments in one of the laboratories. 3 plot. Underwater cleaning laboratory. The captain of the ship at the helm. The process of the technological cycle of water purification using a special underwater vehicle during the movement of the ship. NDP on treatment facilities. Experts write off the meter readings, take water analysis in the laboratory. Draftsmen at the drawing boards in the design office. NDP. The scuba diver dives under water. 4 plot. On the sailing ship "Druzhba". Ship "Friendship" under sail at sea. Sailors on deck. One of the sailors washes the deck with a hose. Sailors during training and practical training: learn to navigate the ship, fold and strengthen the sails, receive certificates of honor on the upper deck.