On July 8, 2005, approximately 1130 Pacific daylight time, the wing of a Cessna 206E, N9428G, impacted the runway during the landing roll at Stuart Island Airstrip (East), Stuart Island, Washington. The airline transport pilot, who was the sole occupant, was not injured, but the aircraft, which is owned and operated by Aeronautical Services, of Friday Harbor, Washington, sustained substantial damage. The 14 CFR Part 135 cargo flight, which departed Eastsound Airport, Orcas Island, Washington, about 10 minutes prior to the accident, was being operated in an area of low clouds, rain, and mist. The aircraft had been on a company VFR flight plan. There was no report of an ELT activation. According to the pilot, due to the restrictions created by marginal VFR conditions, he entered the pattern on a close-in dogleg to final for a landing to the west. Just as he was starting to turn final, he heard another pilot broadcast that he was departing Stuart Island to the east. The pilot of N9428G therefore transmitted, "Aircraft close in, landing to the west, Stuart". He then prepared to execute a go-around. As he rounded the corner of the island and rolled out on final, the pilot saw an aircraft pull off of the runway to the grassy area to its south. He therefore decided to continue his approach to a full-stop landing. Upon touchdown on the 2,000 foot runway, the aircraft encountered a significant amount of standing water, and the pilot immediately retracted the flaps in order to get more weight on the wheels for braking. Because of the amount of standing water, the aircraft began to hydroplane, and as it neared the end of the runway, it still had not come to a stop. In an attempt to keep the aircraft from going off the far end of the runway, the pilot intentionally executed a sharp turn to the right. Just after the turn was initiated, the left main gear and the nose gear dug into the soft muddy surface, resulting in the aircraft tipping up on its left side and the left wing contacting the runway surface. During the investigation it was determined that a heavy rain shower had passed through the area about 15 minutes prior to the landing of N9428G, and that there was still a significant portion of the runway surface that had standing water on it. During a post-accident interview, the pilot stated that he did not realize that there was so much standing water on the runway until after he touched down and it started spraying up on the bottom of the wings and onto the windshield. He further stated that if he had realized that the potential for hydroplaning was so great, he would have slowed his approach speed to compensate for the overly-wet conditions.