On February 9, 1997, about 1115 eastern standard time, a Cessna 150F, N6679F, collided with a lake during final landing approach to the Winter Haven's Gilbert Airport, Winter Haven, Florida. The airplane was operated under the provisions of Title 14 CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed. A flight plan was not filed for the solo, instructional flight. There were no injuries to the student pilot, and the airplane was substantially damaged. Origination of the flight was Winter Haven, about 1100, on the same day. According to the operator, the student pilot had flown a dual flight on the previous day. He then flew another dual flight on the morning of the accident, and was sent out for his second solo flight. After one circuit in the landing pattern, while on the second landing approach of the solo flight, the engine did not respond to increased throttle movement. The student pilot stated he "noticed some difference in the craft on left base leg of runway 4." When he turned final for runway 4, he noticed that he was "somewhat low for usual or desired glide path and began applying power. The craft did not respond." The pilot then stated he applied full power, and the airplane still did not respond to the power. At this point, the student stated he realized he would not make the runway and ditched the airplane in a lake. The airplane nosed over in the water. An FAA inspector examined the airplane and found damage to the lower cowling, the right wing, and the right aileron. He also noted that the throttle was in the full open position, properly connected, and operating normally. The mixture control was found in the idle-cutoff position, properly connected, and operating normally. Also, the carburetor heat was found in the cold position, properly connected, and operating normally.