On April 6, 1996 about 1600 eastern standard time, a Cessna 210M, N700RP, collided with the water after running off the end of runway 15 during landing at Everglades Airport, Everglades City, Florida. The aircraft was operated by the pilot under the provisions of Title 14 CFR Part 91, and visual flight rules. A flight plan was not filed for this personal flight, and visual meteorological conditions prevailed. The private pilot and his passenger were not injured; the aircraft was substantially damaged. The flight departed Ft. Lauderdale Executive Airport about 1515 on that same day. According to the pilot, during the landing attempt, the airplane touched down 1000 feet down the 2400 foot long runway. This would leave the pilot 1400 feet to stop the aircraft after touchdown, with the landing ground roll for this type of aircraft is 765 feet. The airplane rolled off the runway into the grass, and came to rest in the water approximately 145 feet from the end of the runway, incorporating the path angle. During the examination of the runway, there was a 472 foot black skid mark observed leading to the left main landing gear on the runway; there was not a skid mark leading to the right main landing gear. It was observed the left main tire was flat with a hole, indicating it had been worn from breaking. While inspecting the aircraft's brake system, there were indications of hydraulic fluid leakage on the right main landing gear leg at the pivot joint which allows movement of the gear leg during retraction. This fluid loss would account for the loss of brake pressure on the right brake, as it was determined to be totally inoperative. The right tire was fully inflated and showed no signs of excessive wear. The mechanic who inspected the aircraft stated that in his opinion, the pilot would not have had any braking ability at all in the right brake. The pilot reported that recent brake maintenance had been performed on the airplane.