UPDATE 20100716 @ 1548: I received an email from Jorge Piñon (Visiting Research Fellow with the Cuban Research Institute at Florida International University and former president of Amoco Oil Latin America) pointing out that the Russians are not in deep waters, in fact, they are in two blocks of shallow waters as seen in the map (click image to expand further).
20100714 @ 0825: Russian state oil company Zarubezhneft plans to drill a shelf near Cuba in 2011. Zarubezhneft and the Cuban national oil company, Cubapetroleo, signed four contracts in November 2009 to conduct geologic explorations and hydrocarbon production. The contracts were the first long-term contracts between Russia and Cuba in the last 20 years. [RIA Novosti]