On September 27, 2005, at 1115 central daylight time, a Cessna T206H amphibian, N206WK, sank following a collision with an unexpected wave while landing on the waters of Sturgeon Bay in near Sturgeon Bay, Wisconsin. The pilot was not injured. The airplane was substantially damaged. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions without a flight plan. The flight originated from the Green Bay-Straubel Airport (GRB), Green Bay, Wisconsin, at 1110. The pilot stated he made two landings near Little Sturgeon Bay while en route to Sturgeon Bay. He stated that once reaching Sturgeon Bay he flew over the intended landing area which he was very familiar with. He stated the water looked clear so he approached the channel on a downwind leg. He stated he turned base leg over the shoreline and turned onto final approach into the wind. He stated that when he entered the landing flare he looked out his side window to judge his height and he "saw a very large wave" that was in his path. He stated that there was no way to avoid the wave so he added power to try and "catch the top of the wave." However, the floats caught the wave and the airplane was "catapulted" forward into the water. The tip of the right float broke off and the airplane sank nose down in 10 to 12 foot deep water. The pilot reported there was approximately a 6-inch chop of the surface of the water at the time of the landing. He stated he was landing to the southwest and the winds were from the southwest at approximately 12 knots.