For more information about seamen, see the Deckhands specialty. Oilers work with the engineers. They lubricate gears, bearings, and other moving parts of engines and motors. They also read pressure and temperature gauges. Oilers record data and may repair and adjust machinery.
Pilots guide ships in and out of harbors and other waterways.
They have knowledge of the local water depths, winds, tides, and hazards that the regular crewmembers do not have. Harbor pilots often pilot ships for just one day. River and canal vessels often have pilots as regular crewmembers. The size of the crew varies by the type of ship and the location. A typical deep sea merchant ship has a captain, three mates, a chief engineer, three assistant engineers, plus six or more deckhands and oilers.