The way the wing rigger is mounted on the boat generates less stress for the boat itself and so improves its propulsion through the water. Boat profile remains practically constant during all stroke phases on account of the lower stress forces applied. Since aluminium is a deformable material, elastic energy will be absorbed by deformation of the rigger itself. This is a relatively limited problem, however, since the energy will be released in the direction of propulsion along a plane parallel to the water. Rigger stiffness has been improved by giving the segment going from the boat to the oarlock a conical shape while the inboard segment is cylindrical. In addition, the inboard segment does not lie perfectly along the centre line across the boat but is slightly inclined so as to allow more balanced dispersion of load stresses onto the gunwales. Forward pitch, span or spread can be easily adjusted thanks to the drill holes in the gunwale and the slots on the end of the rigger.