On November 20, 1997, about 1600 eastern standard time, a Cessna 152, N93286, overran the end of the grass runway, collided with a ditch, and nosed over at Shell Creek Airpark, Punta Gorda, Florida. The airplane was operated by Professional Aviation under the provisions of Title 14 CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed. A flight plan was not filed for the local fight. The certified flight instructor (CFI) and student pilot received minor injuries, and the airplane was substantially damaged. The flight originated in Punta Gorda, Florida at 1430. According to the CFI, the student was attempting a short and soft takeoff from Shell Creek, a grass strip. The wind was light and variable. He believed the grass was about 1 foot long, and looked wet. The student rotated about halfway down the 2600 foot runway. While in ground effect, the instructor decided to abort the takeoff due to a lack of airspeed to clear the obstacles at the end of the runway. The CFI then pulled the power to idle and pitched down for landing. The instructor said, using maximum braking, the airplane was not able to stop before colliding with bushes and encountering a ditch. The airplane then nosed over. The instructor reported having no mechanical problems prior to the accident. A witness stated he saw the airplane begin its takeoff roll, and that it appeared to have 10 degrees of flaps extended. As it left his sight, the nose wheel was off the ground. Shortly thereafter, he heard the engine "suddenly pull back". He then heard a very loud noise. He stated the grass was mowed the day before, and it had not rained in over a week. Two other witnesses confirmed that the grass was dry and mowed the day before. The Information Manual for a similar make and model airplane was consulted. The manual stated that with 10 degrees of flaps, using short field technique, at a weight of 1,640 lbs., a lift off speed of 50 KIAS, pressure altitude of 2,000 feet, temperature 30 degrees C., the total take off distance to clear a 50 foot obstacle would be 1,820 feet. A dry grass runway would increase the take off distance by 147 feet, or a total of 1,967 feet.