FIELD: development of ocean; submersible vehicles-buoys having varying buoyancy. SUBSTANCE: method is based on use of difference of temperatures of water on surface and in depth of world ocean. Method is also based on use of thermal expansion of working medium for motion of movable rod inside vehicle and return of this rod when working medium is cooled. Used as working medium is boiling liquid contained in closed reservoir at temperature above 0 C in equilibrium with it vapor at pressure of saturated vapors. Submersible vehicle is positioned in upper in upper point of trajectory till working medium is heated to surrounding temperature and saturated vapor pressure rises to respective level; then piston is set in free motion during displacement of rod connected with this piston inside vehicle. When submersible vehicle comes to lower point of trajectory it has neutral buoyancy till working medium is cooled to surrounding temperature, vapors are condensed and saturated vapor pressure reduces; then piston is released during extension of rod beyond pressure hull. EFFECT: extended range of buoyancy variation and enhanced reliability of submersible vehicle. 4 cl, 2 dwg
