N573TB

According to the pilot he and his passenger departed from a lake marina on a local flight to conduct water take offs and landings. The flight was uneventful, but during the landing approach, the pilot reported that he misjudged the flare height due to the lack of visual reference on the water surface. He flared the airplane high and subsequently landed hard. Post-accident investigation revealed that the left forward float strut attachment point and lower left frame tube was sustained substantial damage. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.