Ocean Rig UDW Inc. is an operator of semi-submersible oil rigs and UDW drillships based in Athens, Greece. The company also maintains offices in Luanda, Angola, Aberdeen, Scotland, Jersey, Rio de Janeiro, Brazil and Stavanger, Norway.. The company has two semi-submersibles, the Leiv Eiriksson and Eirik Raude, and four ultra deepwater drill ships "Ocean Rig Olympia", "Ocean Rig Mykonos", "Ocean Rig Poseidon" and "Ocean Rig Corcovado".