Abstract: The invention pertains to tensioners for maintaining a load between two relatively movable structures, such as an offshore drill ship or the like and a riser pipe. First and second tensioner bodies are mounted for relative reciprocation, and are further functionally interconnected with the first and second offshore structures respectively. Relative movement of the offshore structures tends to cause corresponding relative reciprocation of the tensioner bodies. A force is applied between the tensioner bodies tending to reciprocate them in a first directional mode and thereby supporting the offshore riser pipe with respect to the offshore support structure. A balancing chamber cooperative between the tensioner bodies communicates with a source of pressurized fluid for resisting reciprocation of the tensioner bodies in the first directional mode, but includes an outlet for egress of the pressurized fluid to permit such reciprocation under controlled conditions.