The pilot was performing a repositioning flight following the completion of an annual inspection. After departing from a runway in his amphibious airplane, he observed a large, open area on a nearby lake and decided to perform a touch-and-go landing. Upon touchdown, the airplane flipped over and came to rest inverted, resulting in substantial damage to the fuselage and wings. Due to his injuries, the pilot had no recollection of the accident. An inspector with the Federal Aviation Administration reported that, during wreckage recovery from the lake, all four landing gear wheels were in the extended positions, and the landing gear handle was in the “Down Land” position. He also noted that the pilot tube was covered in black electrical tape, blocking airflow through the tube. A pitot/static discrepancy was found during the annual inspection and the repair was deferred. The airplane was equipped with a backup landing gear position advisory system that would provide an audible message confirming the position of the gear prior to landing; however, the audible component would not work properly if the pilot tube was obstructed.