On September 20, 2007, about 1230 Pacific daylight time, a Cessna 340A, C-FTPA, overran the runway at Sonoma Valley Airport, Schellville, California. Tiger Paw Aviation Corporation was operating the airplane under the provisions of 14 CFR Part 91. The commercial pilot and one passenger were not injured; the airplane sustained substantial damage. The personal cross-country flight departed Boise Air Terminal, Boise, Idaho, about 1145, with a planned destination of Gnoss Field Airport, Novato, California. Visual meteorological conditions prevailed, and an IFR flight plan had been filed. In a written report to the National Transportation Safety Board, the pilot stated he was cleared by ATC for a visual approach into Gnoss Field. He acknowledged an airport in sight and flew a standard pattern for landing. The pilot landed, overran the 1,500-foot runway, and came to rest in a vineyard on the departure end of the runway. He mistook the accident airport for his destination, which is nearby and has a 3,300-foot runway. The pilot also noted that the runway's wet conditions hindered breaking and caused the airplane to hydroplane. The pilot reported no preimpact mechanical malfunctions or failures with the airframe or engine. Review of the airplane's landing performance chart revealed that if the pilot landed the airplane at maximum gross weight with full flaps extended, a ground roll of about 790 feet would have been required to stop on a dry runway. According to the FAA Airplane Flying Handbook, hydroplaning is a condition that can exist when an airplane lands on a runway surface contaminated with standing water. Hydroplaning can have serious adverse effects on ground controllability and braking efficiency.