On July 11, 1993, about 1955 central daylight time, a two-place Maxair Drifter MU532 airplane, owned and piloted by John R. Diebel descended to a water impact while maneuvering over Pistakee Lake, near Fox Lake, Illinois. The sole occupant was seriously injured, and the airplane received substantial damage. Visual meteorological conditions existed for the personal flight operated under 14 CFR Part 91. The flight originated from an unknown location. No flight plan was filed. The operator did not hold FAA pilot or medical certificates. The construction of the Maxair Drifter did not comply with the requirements of FAR Part 103. The airplane did not have FAA registration or airworthiness certificates. The operator did not hold or operate the Maxair Drifter in accordance with the conditions of an exemption. On July 21, 1993, an NTSB Form 6120.1/2 was forwarded to Mr. Diebel for completion and submission. This form has not been returned. The wreckage was towed to a nearby marina. To facilitate towing and storage, the wings, landing gear, and fuel containers were disassembled. Personnel from the marina ran the engine to purge it of any water. Investigation of the airplane revealed the following: The longitudinal support attaching the empennage was severed into two pieces, the propeller blades of the pusher-mounted engine were severed almost to the hub. The cockpit area and remaining structures were intact and relatively undamaged. Except for some of the hardware, none of the seatbelts, instruments, or other components were of aircraft quality or had any TSO markings. The assembly techniques were not in accordance with acceptable FAA maintenance practices. Approximately nine gallons of automotive fuel was contained in two interconnected plastic five-gallon containers strapped onto individual racks and located behind the aft seat. The permanent fuel line fitting that connected the containers was broken.