FIELD: navigation. SUBSTANCE: geometrical device mounted in well at depth of hot strata whose temperature does not exceed 353 K has geothermal pipe closed at ends with peripheral and inner walls between which stiffeners run along generatrices and two walls which divide chamber formed by inner wall in half. Lower part of inner wall is made of light alloy and is lowered deeper than peripheral wall together with walls dividing the chamber; at top, chambers of inner wall are connected with ground piping system where river water is used as geothermal agent because no ground energy is required for pumping this agent. Geothermal device and its piping system are located on banks of navigable rivers making use of underground heat for year-round navigation; device is ecologically pure and economically effective for realization. EFFECT: ecologically pure device which enhanced economical efficiency. 5 dwg
