The textbook describes the theory and fundamentals of the operation of technical means of navigation of river vessels and vessels of mixed river - sea navigation. The consideration is based on the analysis of structural and functional diagrams of devices. The presentation in the textbook of the material of the discipline "Technical means of navigation" and partially the material of the discipline "Radioelectronics and radio navigation devices" makes it possible for the future boatmaster to get an idea of ​ ​ the joint operation of modern technical means of navigation and radio navigation devices.