On July 1, 2003, at 1430 central daylight time, a Cessna A185F, N30CM, piloted by a private pilot, sustained substantial damage when it overran runway 36 (1,800 feet by 100 feet, grass/turf) and went into a ditch at the Sky Harbor Seaplane Base, Eveleth, Minnesota. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions without a flight plan. The pilot and passenger were not injured. The flight originated from the Manitowish Waters Airport, Manitowish Waters, Wisconsin, at 1310. The runway is adjacent to the seaplane base and is used by aircraft coming to the base to have floats installed. In a written report, the pilot stated that on his first landing approach, he noticed a mower on the runway and aborted the landing. He contacted the airport to have the mower exit the runway. The pilot stated that he circled the airstrip 2 to 3 times before making another landing attempt. On the second landing attempt, the mower had moved to the right side of the runway about 1/4 of the way down the length of the runway. The pilot stated that he landed past the location of the mower, touching down past the halfway point on the runway. He reported that the airplane was too fast to stop on the grass runway, subsequently impacting the ditch embankment. The pilot reported no mechanical difficulties with the airplane. A weather reporting station about 2 nautical miles and 200 degrees from the accident site recorded the wind at 1436 as 230 degrees at 8 knots. The tailwind component was calculated to be 5 knots.