Seawise Giant (known later as the Happy Giant, Jahre Viking, Knock Nevis, Oppama, and Mont) was a ULCC supertanker. It was the longest ship ever built and had the greatest deadweight tonnage that has ever been recorded. When it was heavily loaded, the ship had a displacement of 657,019 tonnes (646,642 long tons; 724,239 short tons) and had a draft of 24.6 m (81 ft). Due to it's size and lack of maneuverability, it was not able to move through the English Channel, Suez Canal or the Panama Canal.