A seismic source configured to generate acoustic waves, the seismic source comprising: a housing having a firing chamber, a triggering chamber, a purge chamber, and a hydraulic chamber, the hydraulic chamber having at least one opening port (512, 514) communicating with an ambient; a movable shuttle having a first piston separated from a second piston by a neck, wherein the movable shuttle is movable between: - a closed position for which the first piston separates the firing chamber from the hydraulic chamber, and the second piston separates the firing chamber from the triggering chamber; and - an open position for which compressed gas from the firing chamber escapes through the at least one opening port (512, 514) into the ambient, a compensator block located inside the housing and separating the triggering chamber from the purge chamber, wherein the compensator block is configured to move along a longitudinal axis X of the housing; the triggering chamber being formed between the compensator block and the second piston when the movable shuttle is in the closed position; a first static seal system configured to seal a first interface between a surface of the housing and a surface of the first piston in the closed position, the first static seal system being not subject to friction when a relative movement between the first piston and the housing generates a gap between said surfaces of the housing and said first piston; and a second static seal system configured to seal a second interface between a surface of the second piston and a surface of the compensator block in the closed position, the second static seal system being not subject to friction when a relative movement between the second piston and the housing generates a gap between said surfaces of the housing and said second piston, wherein the compensator block is configured to move less along the longitudinal axis than the movable shuttle, wherein the seismic source includes a pressure mechanism configured to, in view of firing the seismic source, increase the pressure in the triggering chamber, to move the compensator block along the longitudinal axis X in one direction and make the shuttle to move along the longitudinal axis X in an opposite direction, to the open position. a housing having a firing chamber, a triggering chamber, a purge chamber, and a hydraulic chamber, the hydraulic chamber having at least one opening port (512, 514) communicating with an ambient; a movable shuttle having a first piston separated from a second piston by a neck, wherein the movable shuttle is movable between: - a closed position for which the first piston separates the firing chamber from the hydraulic chamber, and the second piston separates the firing chamber from the triggering chamber; and - an open position for which compressed gas from the firing chamber escapes through the at least one opening port (512, 514) into the ambient, - a closed position for which the first piston separates the firing chamber from the hydraulic chamber, and the second piston separates the firing chamber from the triggering chamber; and - an open position for which compressed gas from the firing chamber escapes through the at least one opening port (512, 514) into the ambient, a compensator block located inside the housing and separating the triggering chamber from the purge chamber, wherein the compensator block is configured to move along a longitudinal axis X of the housing; the triggering chamber being formed between the compensator block and the second piston when the movable shuttle is in the closed position; a first static seal system configured to seal a first interface between a surface of the housing and a surface of the first piston in the closed position, the first static seal system being not subject to friction when a relative movement between the first piston and the housing generates a gap between said surfaces of the housing and said first piston; and a second static seal system configured to seal a second interface between a surface of the second piston and a surface of the compensator block in the closed position, the second static seal system being not subject to friction when a relative movement between the second piston and the housing generates a gap between said surfaces of the housing and said second piston, wherein the compensator block is configured to move less along the longitudinal axis than the movable shuttle, wherein the seismic source includes a pressure mechanism configured to, in view of firing the seismic source, increase the pressure in the triggering chamber, to move the compensator block along the longitudinal axis X in one direction and make the shuttle to move along the longitudinal axis X in an opposite direction, to the open position.