Exchange, at which time its shares were removed from the Swiss Market Index. Effective on January 30, 2018, the company completed its acquisition of Songa Offshore. In December 2018, the company acquired Ocean Rig. Controversies Accidents and incidents Transocean was rated as a leader in its industry for many years. However, since the company's 2007 merger with GlobalSantaFe, Transocean's reputation has suffered considerably, according to EnergyPoint Research, an independent oil service industry rating firm. From 2004 to 2007, Transocean was the leader or near the top among deep-water drillers in "job quality" and "overall satisfaction." In 2008 and 2009, surveys ranked Transocean as last among deep-water drillers for "job quality" and next to last in "overall satisfaction." In 2008 and 2009, Transocean ranked first for in-house safety and environmental policies, and in the middle of the pack for perceived environmental and safety record. The Deepwater Horizon explosion and massive oil spill, starting in April 2010, further hurt its reputation. "Transocean is dominant, but the accident has definitely tarnished its reputation for worker safety and for being able to manage and deliver on extraordinarily complex deepwater projects," said Christopher Ruppel, an energy expert and managing director of capital markets at Execution Noble, an investment bank. Transocean Leader accident (2002) On 2 March 2002, a Scottish man was killed in an accident aboard the Transocean Leader drilling rig operated for BP, located about 138 kilometers (86 miles) west of Shetland, Scotland. Galveston Bay explosion (2003) On 17 June 2003, one worker was killed, four others were hospitalised and 21 were evacuated after an explosion on a Transocean gas drilling rig in Galveston Bay, Texas. Maintenance citation on Transocean Rather (2005) On 24 August 2005, the UK Health and Safety Executive issued a notice to Transocean saying that, it had failed to maintain its "remote blowout preventor control panel … in an efficient state, efficient working order and in good repair." On 21 November 2005, Transocean was found to be in compliance for this matter. Sinking of Bourbon Dolphin supply boat /Transocean Rather accident (2007) On 12 April 2007, the Bourbon Dolphin supply boat sank off the coast of Scotland while servicing the Transocean Rather drilling rig, killing eight people. The Norwegian Ministry of Justice established a Commission of Inquiry to investigate the incident, and the commission's report found a series of "unfortunate circumstances" led to the accident "with many of them linked