A film about the research voyage of the ship "Professor Bogorov", about the underwater world of the Indian Ocean. Landscapes of the sea, seagulls. Expedition to the islands of the Indian Ocean by workers of the Pacific Institute of Bioorganic Chemistry under the leadership of A.F. Pavlenko. The members of the expedition sail on the motor ship "Professor Bogorov", a research vessel of the Far Eastern Scientific Center. Ship at sea. Scientists collect marine organisms on the ocean coast, conduct research in the laboratory, dive into the ocean in diving suits, photograph fish underwater, and conduct underwater filming. The doctor examines the members of the expedition. Types of representatives of the ocean fauna: corals, reefs, crabs, starfish, sea urchins, jellyfish, shark, moray eels, zebra fish, sea turtles and worms, octopus and others. The tropical nature of the shores of East Africa. The members of the expedition visit the Seychelles, Mozambique, Madagascar, the People's Democratic Republic of Yemen, see the sights, historical and architectural monuments. Local residents are helping researchers.