[ASSURAS] A final note for now on deepwater drilling. Nations around the globe have been developing techniques and designing equipment for decades. More than 40 years ago, Scotland unveiled the Mercury, a drilling vessel it called "revolutionary." Take a look in this energyTHEN from 1969.

[ANNOUNCER] Scotland -- moving into position for tests at Gairloch was the new rig, the Offshore Mercury, a vessel that will revolutionize deep-sea drilling, for the Mercury is the world's first self-propelled oceangoing drilling vessel, a rig that needs neither tugs nor anchors and can sail 7,000 miles without replenishment. When in action, the derricks are jacked down to the seabed by operating this interior control panel, leaving the hull poised in the air. In the search for gas, oil, and other minerals, the rig is a big step into the future.

[ASSURAS] Today there are 326 offshore oil and gas drilling rigs in the world. 33 of those belong to U.S. companies and 32 are in the Gulf of Mexico.