A barge comprising a hull resting on a plurality of leg systems for grounding the barge and damping the effects of swell, each leg system comprising: • a leg forming a support suitable for being lowered out from the hull and for being raised into the hull; • a hydraulic circuit for lowering the leg out from the barge so as to put it into contact with the sea bottom during grounding of the barge and for raising it into the barge when the barge is floated; characterized in that it further comprises: • a pneumatic circuit for enabling the effects of swell on the barge to be damped, the circuit comprising: • a cylinder inside which there slides a piston connected to one end of the leg, the piston subdividing the volume of the cylinder into a bottom chamber and a top chamber that are distinct from each other; • filler means for filling the two chambers of the cylinder with water and for emptying them in order to lower and raise the leg; • a leaktight and deformable membrane that is positioned in the top chamber of the cylinder in order to define a pneumatic damper chamber inside the top of said chamber; • injection means for injecting compressible gas into the pneumatic damper chamber of the cylinder; and • control means for controlling the pressure of the gas inside the pneumatic damper chamber of the cylinder. • a leg forming a support suitable for being lowered out from the hull and for being raised into the hull; • a hydraulic circuit for lowering the leg out from the barge so as to put it into contact with the sea bottom during grounding of the barge and for raising it into the barge when the barge is floated; characterized in that it further comprises: • a pneumatic circuit for enabling the effects of swell on the barge to be damped, the circuit comprising: • a cylinder inside which there slides a piston connected to one end of the leg, the piston subdividing the volume of the cylinder into a bottom chamber and a top chamber that are distinct from each other; • filler means for filling the two chambers of the cylinder with water and for emptying them in order to lower and raise the leg; • a leaktight and deformable membrane that is positioned in the top chamber of the cylinder in order to define a pneumatic damper chamber inside the top of said chamber; • injection means for injecting compressible gas into the pneumatic damper chamber of the cylinder; and • control means for controlling the pressure of the gas inside the pneumatic damper chamber of the cylinder. • a pneumatic circuit for enabling the effects of swell on the barge to be damped, the circuit comprising: • a cylinder inside which there slides a piston connected to one end of the leg, the piston subdividing the volume of the cylinder into a bottom chamber and a top chamber that are distinct from each other; • filler means for filling the two chambers of the cylinder with water and for emptying them in order to lower and raise the leg; • a leaktight and deformable membrane that is positioned in the top chamber of the cylinder in order to define a pneumatic damper chamber inside the top of said chamber; • injection means for injecting compressible gas into the pneumatic damper chamber of the cylinder; and • control means for controlling the pressure of the gas inside the pneumatic damper chamber of the cylinder. • a cylinder inside which there slides a piston connected to one end of the leg, the piston subdividing the volume of the cylinder into a bottom chamber and a top chamber that are distinct from each other; • filler means for filling the two chambers of the cylinder with water and for emptying them in order to lower and raise the leg; • a leaktight and deformable membrane that is positioned in the top chamber of the cylinder in order to define a pneumatic damper chamber inside the top of said chamber; • injection means for injecting compressible gas into the pneumatic damper chamber of the cylinder; and • control means for controlling the pressure of the gas inside the pneumatic damper chamber of the cylinder.