Found this report from The Times on encarta:
A 220,000-ton Liberian supertanker was said to be listing six degrees in the South Atlantic last night, after being bombed by an unidentified four-engined, propeller-driven aircraft.
The incident happened 480 miles north-east of the Falklands, as the tanker, the Hercules, was heading for Alaska, around Cape Horn from the Virgin Islands, to load up with crude oil. No details of damage or casualties are known, the vessel did not report being in a dangerous condition, and was said to be making for a Brazilian port.
The description of the aircraft suggests a Hercules C130 transport—possibly an Argentine machine searching for British task force ships on their way to and from Ascension Island. There have been previous stories of the Argentines using C130s to drop bombs at a range beyond that of other Argentine aircraft.
Interesting anyone know more about this?