On October 20, 2002, about 1450 eastern daylight time, a Cessna 152, N47147, was substantially damaged during a forced landing after it experienced a total loss of engine power near Salisbury, Massachusetts. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the personal flight that departed the Beverly Municipal Airport (BVY), Beverly, Massachusetts. The flight was conducted under 14 CFR Part 91. The airplane was based at the Lawrence Municipal Airport (LWM), Lawrence, Massachusetts. In a written statement, the pilot reported that on the morning of the accident, he arrived at LWM and performed a preflight inspection of the airplane. The airplane was parked outside for over a week, and during the preflight inspection, he observed water in the fuel system. The pilot drained the fuel system until he observed no evidence of water contamination and then completed an uneventful 15 minute flight to BVY. Later in the day, the pilot performed a preflight inspection of the airplane and again observed water in the airplane's fuel system. After draining the fuel system, the pilot started the engine, and allowed the engine to operate for "well over 15 minutes," prior to takeoff. The airplane departed BVY uneventfully. The pilot was flying over Salisbury Beach State Park, at an altitude of about 1,000 feet, when he experienced a total loss of engine power, while performing a left turn. The pilot was unable to restart the engine and performed a forced landing to a marsh area. After touchdown, the airplane nosed over. Post accident examination of the airplane and engine by a Federal Aviation Administration inspector, which included draining fuel samples from both wing fuel tanks, the gascolator and the carburetor, revealed "significant" amounts of water contamination throughout airplane's fuel system. The undersides of both the right and left wing fuel caps exhibited evidence of corrosion. The right wing fuel cap seal was severely worn and cracked. A check of weather observations reported at LWM, during the two week period prior to the accident, revealed several observations which included precipitation. The airplane had been operated for about 15 hours since it's most recent annual inspection, which was performed about 2 months prior to the accident.