Incident Overview
A pilot reported that during a low-level aerial photography flight, the engine began to run rough approximately 2 hours and 45 minutes after departure. Shortly thereafter, the engine lost power completely, forcing the pilot to make a landing in a marsh. During the landing, the airplane nosed over.
Post-Crash Examination
Following the accident, an examination of the airplane revealed evidence of water contamination in the fuel system. The contamination was noted as a likely factor in the engine's failure.
Pilot Remarks
The pilot stated that the airplane had been fueled about 20 minutes prior to departure and that he had drained the fuel sumps after fueling. He also noted that he had flown the airplane for a total of 6 hours on the previous day without any issues.