Following an overhead join, the pilot judged his approach to land to be high and fast so decided to go around. The second approach was also high and fast; however, the pilot made the decision to land. The aircraft touched down late but could not be brought to a stop before the end of the runway. Before running out of runway and colliding head on with the airfield boundary hedge beyond, the pilot turned the aircraft right but was unable to prevent colliding with the hedge (in front of which was a shallow ditch). The pilot, who was wearing a full harness, was unhurt and exited the aircraft unaided.