Today, most oilers are employed aboard ships, as this is the only industry which still makes use of the position. Also called "greasers," oilers are unlicensed and among the lowest-ranking employees on a ship, and only a wiper is junior to an oiler.
Although oilers are primarily responsible for maintaining proper lubrication levels for all equipment, other important duties include assisting in bulk fuel transfers, loading and unloading cargo, operating the ship's boats, and maintaining all systems on-board the ship from propulsion and sewage to air-conditioning. They are often required to stand watch on-deck and perform maintenance chores such as cleaning, painting, and repairing lines, and some may also assist engineers with repairs and adjustments, record information from pressure and temperature displays to ensure that all levels are within normal ranges, and even stand at the helm to ensure that the ship stays on-course based on the compass reading desired by the captain.
Aspiring oilers should obtain certification from the United States Coast Guard in the form of a Merchant Mariner's document. Training in firefighting and first-aid is also required, as is documentation in the oiler's respective country. A separate certification may also be required for oilers who will work aboard a liquid-carrying vessel.