Crude tankers are large ships that transport crude oil from one location to another. They are also known as oilers, which is a six-letter term that can be found in crosswords. Crude tankers are typically very large vessels, capable of carrying up to two million barrels of crude oil. They are designed to be able to navigate through rough seas and are equipped with advanced safety features. The crew of a crude tanker consists of highly trained professionals who are responsible for the safe operation of the vessel.