The Sea Quest This semisub discovered the first North Sea oil on Arbroath. A year later, in 1970, she discovered BP’s Forties. She was built in 1966 by BP at the Harland and Wolf yard in Belfast. The design was based on 3 columns, 11m in diameter. She was sold to Sedco in 1977, but in 1980, was damaged in a blow out in Nigeria. Following this, she was sunk in deep water