Oil tanker
Merchant oil tankers carry a wide range of hydrocarbon liquids ranging from crude oil to refined petroleum products. Their size is measured in deadweight metric tons (DWT). Crude carriers are among the largest, ranging from 55,000 DWT Panamax-sized vessels to ultra-large crude carriers (ULCCs) of over 440,000 DWT. Smaller tankers, ranging from well under 10,000 DWT to 80,000 DWT Panamax vessels, generally carry refined petroleum products, and are known as product tankers. The smallest tankers, with capacities under 10,000 DWT generally work near-coastal and inland waterways. [Oil tanker. Wikipedia]