Fire boat response crews battle the blazing remnants of the offshore oil rig Deepwater Horizon, off Louisiana, in this April 21, 2010 file handout image. Photo - Reuters Washington: A US judge's watershed ruling means the final cost to BP for the 2010 Gulf oil spill may eclipse $50 billion, wiping out years of profits and highlighting the risks of drilling as the industry pushes into more dangerous areas such as deeper waters and ice-bound Arctic fields.