Marine safety is one of the eleven missions of the United States Coast Guard. Coast Guard personnel inspect commercial vessels, respond to pollution, investigate marine casualties and merchant mariners, manage waterways, and license merchant mariners. Coast Guard officials also draft recommendations for the transit of hazardous cargo by ship, such as liquid natural gas. In addition to this mission, the Coast Guard carries out investigations to determine the cause of accidents on American-flagged (Flag State) ships or foreign ships in American waters (Port State).