At about 14:04 PST, an amateur-built Aventura II nosed over while landing in a lake about 10 miles east of Antioch. The two occupants suffered minor injuries. The pilot told investigators he took off in the amphibious airplane from an asphalt runway at Byron and flew to a lake near Antioch. The pilot stated that during the approach to an amphibious landing he forgot to retract the landing gear wheels. Upon touchdown, the airplane nosed over.