Description:The disaster following the explosion on drilling rig Deepwater Horizon, in the Gulf of Mexico in 2010, dramatically demonstrated that offshore extraction and exploitation of hydrocarbons is not without risks. Accidents can occur, often with devastating consequences to human lives, expensive extraction equipment, the sea and coastal environment and ecosystem, coastal economies and interruption - or delay - of energy supply. In order for offshore oil and gas operations to become safer, lessons from the analysis of past accidents need to be identified and shared. This report investigates sources of information on offshore accidents, identifies lessons to be learned from "landmark" accidents and how they fit in the risk management chain, and performs statistical analysis based on the content of a commercial accident database.