The pilot reported that he was departing to the southwest in a float-equipped airplane, operated under Title 14, Code of Federal Regulations Part 91. He said that variable south-southeasterly winds required a correction for a left crosswind during his takeoff run. As the airplane climbed to 70 feet above the water, the airspeed began to decrease, and the airplane stopped climbing as it neared the departure end of the lake. In the pilot's written statement to the NTSB he stated, in part: “It became apparent that the aircraft would not clear the trees at the end of the lake and there was insufficient room to land straight ahead.” The pilot indicated that as he turned the airplane to the left to avoid the trees, he lowered the nose to keep from stalling the airplane, and it descended at a high rate. The airplane’s floats struck the water, and the floats to fuselage struts collapsed. The airplane sustained substantial damage to the wings and wing lift struts. The pilot indicated that there were no preaccident mechanical problems with the airplane. He noted in his written statement to the NTSB that the accident might have been avoided if he had delayed his takeoff and waited for more favorable wind conditions, and if he had operated the airplane at a lower gross weight.