The two airplanes collided in mid-air about six miles north of Tacoma Narrows Airport (TIW), Tacoma, Wash., at approximately 1245 Pacific time. The private pilot and sole occupant of the Cessna 182A was not injured. The private pilot of the American Champion Aircraft 7GCBC was not injured; his passenger sustained minor injuries. Visual conditions prevailed. The Cessna departed from Pierce County Airport-Thun Field (PLU) approximately 15 minutes before the accident. The 7GCBC departed from Crest Airpark (S36) at an unknown time with an intended destination of TIW. The Cessna was cruising at 1500 feet msl on a northwesterly heading over Commencement Bay when the collision occurred. The pilot determined that his airplane was still controllable, and he was able to land at PLU without further incident. The 7GCBC was in cruise over Commencement Bay at 1500 feet msl on a southwesterly heading when the pilot heard a loud bang followed by a sudden loss of directional control. The pilot executed a forced landing into Commencement Bay. The pilot and passenger exited the airplane as it began to sink and were rescued by a nearby boat.