The supertanker Torrey Canyon runs aground off the Cornish coast.

SS Torrey Canyon was an LR2 Suezmax class oil tanker with a cargo capacity of 118,285 long tons (120,183 t) of crude oil. She ran aground off the western coast of Cornwall, United Kingdom, on 18 March 1967, causing an environmental disaster. At that time she was the largest vessel ever to be wrecked.

An oil tanker, also known as a petroleum tanker, is a ship designed for the bulk transport of oil or its products. There are two basic types of oil tankers: crude tankers and product tankers. Crude tankers move large quantities of unrefined crude oil from its point of extraction to refineries. Product tankers, generally much smaller, are designed to move refined products from refineries to points near consuming markets.

Oil tankers are often classified by their size as well as their occupation. The size classes range from inland or coastal tankers of a few thousand metric tons of deadweight (DWT) to the mammoth ultra large crude carriers (ULCCs) of 550,000 DWT. Tankers move approximately 2.0 billion metric tons (2.2 billion short tons) of oil every year. Second only to pipelines in terms of efficiency, the average cost of transport of crude oil by tanker amounts to only US$5 to $8 per cubic metre ($0.02 to $0.03 per US gallon).Some specialized types of oil tankers have evolved. One of these is the naval replenishment oiler, a tanker which can fuel a moving vessel. Combination ore-bulk-oil carriers and permanently moored floating storage units are two other variations on the standard oil tanker design. Oil tankers have been involved in a number of damaging and high-profile oil spills. As a result, they are subject to stringent design and operational regulations.