On July 5, 1995, about 1130 Pacific daylight time, a Cessna 182R, N4836E, broke the nose gear during landing at Copalis Beach, WA. The personal flight, operated under 14 CFR 91, last departed Seattle, WA about 0930 hours. Visual meteorological conditions prevailed and no flight plan was filed. The private pilot and the three passengers were not injured. The airplane was substantially damaged. The pilot stated that he was on a pleasure flight and intended to land on a section of beach designated as Copalis State Airport. He flew over the landing area to check the winds and the beach condition. He observed the beach to be smooth with some wet shinny areas. He elected to land at the upper edge of the wet area. During the landing roll, the aircraft hit one of the shinny areas that the pilot thought was a wet spot. The area was actually a pool of water about 6-8 inches deep. When the main gear dropped into the pool the aircraft nosed down, substantially damaging the aircraft.