- Type: Supertanker
- Displacement: 236,710 grt / 564,763 dwt
- Dimensions: 1,504 x 226 x 80 ft.
- Machinery: Sumitomo Stal-Laval AP steam turbines, 50,000PS = 13 knots
- Crew: 40
- Builder: Sumitomo Heavy Industries, Oppama, Japan, 1981
- Notes: Built starting in 1979 for a Greek owner who refused to take delivery due to vibration issues related to faulty gear design. Bought by Hong Kong shipping magnate C.Y.Tung who had her extended enough to make her the largest ship ever built. Finally floated in 1981 and named Seawise Giant. Initially operated between the Middle East and United States, but from 1986 she was used as a floating storage ship and transhipment terminal in Iran. In May 1988, during the Iran-Iraq war, she was attacked and seriously damaged off Iran's Kharg Island. The wreck was towed to Brunei and in 1989 bought by a Norwegian limited liability partnership, the KS-company, managed by Norman International. The ship was repaired by the Keppel Shipyard in Singapore and renamed Happy Giant. Before repairs were completed, however, the Norwegian shipping company Jørgen Jahre took over management and the repaired vessel was delivered as the Jahre Viking. In the late 1990s the majority ownership passed to First Olsen Tankers. In 2004 the ship was refitted at the Dubai Drydocks as a floating storage and offloading unit and renamed Knock Nevis. The ship is now permanently moored in the Al Shaheen oil field of Qatar in the Persian Gulf.