On May 19, 2006, at approximately 1730 Pacific daylight time, an Ercoupe 415-C, N2426H, was substantially damaged during a ditching in the Puget Sound near Vaughn, Washington. The commercial pilot and his passenger were not injured. The pilot/owner was operating the airplane under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the personal, cross-country flight which had originated approximately 10 minutes before the accident from Tacoma Narrows Airport, Tacoma, Washington. A flight plan had not been filed. The pilot said he approached a private runway with the carburetor heat on and the engine's throttle back. He said he descended in a glide from 1,500 feet to 500 feet, and flew over the runway to make sure it was clear of people and obstacles. When he added power back in, the engine sputtered, ran for a short time, and lost power. The pilot said that he picked a place near the shore and ditched in the salty water. He attributed the loss of engine power to carburetor ice.