On June 15, 1997, approximately 1800 mountain daylight time, an experimental Wood Murphy Rebel, N224MR, impacted the water during a takeoff from Middle Thompson Lake near Marion, Montana. The private pilot was not injured, but his passenger received minor injuries, and the aircraft, which was owned and operated by the pilot, sustained substantial damage. The local 14 CFR Part 91 personal pleasure flight was being operated in visual meteorological conditions at the time of the accident. No flight plan had been filed, and the ELT, which was activated by the impact, was turned off at the scene. In a telephone conversation with an FAA inspector, the pilot said that he was taking off into a wind of about ten knots that was gusting to 15 knots. He said that he started a left turn soon after liftoff, and that while turning left, the aircraft entered a downdraft and encountered a gust of wind from the right. This resulted in the aircraft descending while still in a left turn. The pilot was unable to arrest the descent prior to the left float impacting the water, and when the float hit the water, the aircraft flipped over on its back.