A riser tensioner arrangement comprising: a high-pressure accumulator defining an interior volume configured to hold a first high-pressure fluid and a second high-pressure fluid; a cylinder defining an interior volume; a piston slidingly disposed within the interior volume of the cylinder, the piston including a sealing section and an extension section, the sealing section separating the interior volume of the cylinder into a first volume and a second volume, the extension section extending upwardly from the sealing section through the second volume; a first flow path coupling the interior volume of the high-pressure accumulator with the first volume of the cylinder to enable the first high-pressure fluid to flow therebetween; characterized in that a) the extension section of the piston defines a hollow interior that is coupled to the second volume of the cylinder via at least one aperture; b) a second flow path couples the interior volume of the high-pressure accumulator with the second volume of the cylinder, wherein the second flow path enables the second high-pressure fluid to flow between the interior volume of the high-pressure accumulator and the second volume of the cylinder; and c) the pressure of the second fluid stabilizes in use across the arrangement including the hollow interior of the piston extension and the interior of the accumulator. a high-pressure accumulator defining an interior volume configured to hold a first high-pressure fluid and a second high-pressure fluid; a cylinder defining an interior volume; a piston slidingly disposed within the interior volume of the cylinder, the piston including a sealing section and an extension section, the sealing section separating the interior volume of the cylinder into a first volume and a second volume, the extension section extending upwardly from the sealing section through the second volume; a first flow path coupling the interior volume of the high-pressure accumulator with the first volume of the cylinder to enable the first high-pressure fluid to flow therebetween; characterized in that a) the extension section of the piston defines a hollow interior that is coupled to the second volume of the cylinder via at least one aperture; b) a second flow path couples the interior volume of the high-pressure accumulator with the second volume of the cylinder, wherein the second flow path enables the second high-pressure fluid to flow between the interior volume of the high-pressure accumulator and the second volume of the cylinder; and c) the pressure of the second fluid stabilizes in use across the arrangement including the hollow interior of the piston extension and the interior of the accumulator. a) the extension section of the piston defines a hollow interior that is coupled to the second volume of the cylinder via at least one aperture; b) a second flow path couples the interior volume of the high-pressure accumulator with the second volume of the cylinder, wherein the second flow path enables the second high-pressure fluid to flow between the interior volume of the high-pressure accumulator and the second volume of the cylinder; and c) the pressure of the second fluid stabilizes in use across the arrangement including the hollow interior of the piston extension and the interior of the accumulator.