On May 25, 1995, at 0804 central daylight time, a Cessna 180D, sustained substantial damage during landing at the Sky Harbor Seaplane Base in Eveleth, Minnesota. The private pilot and two passengers reported no injuries. The personal, 14 CFR Part 91 flight originated in Milwaukee, Wisconsin. Visual meteorological conditions prevailed and an IFR flight plan was filed. In his written statement the pilot reported that he used what he believed was 20 degrees of flaps and turned onto final approach at an airspeed of 80 knots with the power set at 15 inches of manifold pressure. As he flew over the trees prior to the threshold, he heard the stall warning indicator. He applied full power and the airplane impacted the runway. The airplane bounced and the right wing impacted bushes along the side of the runway. The pilot reported that he examined the airplane following the accident and discovered the flaps were in the 30 degree position. He reported that he had never landed the airplane in this configuration before.