NTSB Factual Report

The pilot reported that about 40 minutes into the over water flight between islands, he requested a descent to 3,400 feet, which was approved by air traffic control. The pilot reduced the engine power to 2,000 rpm; however, the engine rpm dropped to 1,500. Actions by the pilot to restore engine power were unsuccessful. Following a successful water landing, the occupants exited the airplane and were rescued by the United States Coast Guard about 30 minutes later. The airplane subsequently sank and was not recovered.

NTSB Probable Cause

A partial loss of engine power for reasons that could not be determined because the airplane was ditched and not recovered.