German submarine U-507 was a Type IXC U-boat of Nazi Germany's Kriegsmarine built for service in the Second World War and the Battle of the Atlantic. She was mainly notable for two patrols she conducted during the "Second Happy Time" in mid-1942, during the first of which she caused havoc in the Gulf of Mexico amongst unprotected American shipping, and then in the second she attacked ships along the coast of Brazil, in an inexplicable and shocking attack on a neutral nation's shipping in its own waters which almost single-handedly provoked the Brazilian declaration of war on Germany.

The U-boat was built during 1941 by the Deutsche Werft shipyards in Hamburg, and commissioned on 8 October 1941, with Korvettenkapitn Harro Schacht in command. Schacht commanded the boat for its entire lifespan, receiving the Knight's Cross of the Iron Cross on 9 January 1943 in recognition of his successful patrols in the preceding year. He never wore his award however, as he was killed with his entire crew when the boat was sunk four days later.

A tanker (or tank ship or tankship) is a ship designed to transport or store liquids or gases in bulk. Major types of tankship include the oil tanker, the chemical tanker, and gas carrier. Tankers also carry commodities such as vegetable oils, molasses and wine. In the United States Navy and Military Sealift Command, a tanker used to refuel other ships is called an oiler (or replenishment oiler if it can also supply dry stores) but many other navies use the terms tanker and replenishment tanker. Tankers were first developed in the late 19th century as iron and steel hulls and pumping systems were developed. As of 2005, there were just over 4,000 tankers and supertankers 10,000 LT DWT or greater operating worldwide.