The Scarabeo 9 oil rig had to be brought half way around the world to bypass the five-decade-long US trade embargo on Cuba.

After a slow trek by sea from China, it finally arrived in the region last week: a faint hulk on the horizon, shrouded in mist, as it passed Havana's waterfront, the Malecon.

This is a key moment for Cuba.

The island has two on-shore oil facilities that produce half of the oil it needs; it is heavily dependent on socialist ally Venezuela for the rest.

The government imports more than 100,000 barrels a day at subsidised rates, paid for with the services of some 30,000 Cuban doctors and other health officials working in Venezuela.