The significant increase in the level of offshore oil production in recent years requires advanced and complicated technology. The modern technology for oil exploration and production is marching forward into the 21st century. 1 There are now more than 8000 offshore oil platforms and 700 exploration drilling rigs in over 5000 offshore field developments in more than 100 countries. 2 The establishment of various types of installations for the purpose of the exploration and exploitation of oil and gas from offshore resources has given rise to a series oflegal issues in recent years. In the last decade of the 20th century two cases relating to offshore oil rigs were presented to the International Court of Justice: the Case Concerning Passage Through the Great Belt3 and the Oil Plaiforms Case.4