While participating in a soaring contest, the glider pilot entered an area where atmospheric lift was not sufficient. Instead of jettisoning the glider's water ballast to reduce its sink rate and reversing his course toward better outlanding fields, he continued on with the contest course and task. He therefore ultimately ended up in a location where he was forced to attempt an off-airport landing on unsuitable terrain. Immediately upon touchdown, the glider encountered several small boulders that were hidden in the grass, and the left wing tip became snagged in some tall grass, resulting in a loss of directional control. During the resulting ground loop, both wings sustained substantial damage and the empennage tail boom separated from the main part of the fuselage.