On 8 June 1982, she was traversing the South Atlantic, en route to collect a load of crude oil, when she was attacked three times by Argentine aircraft.

Listing, she put into port in Brazil so that the damage could be assessed; it was determined that it was too dangerous to move an unexploded bomb lodged in one of her oil tanks.

[6] The United States Maritime Administration advised both governments by telex of the movements of all US-flagged vessels and also Liberian-flagged tankers with US interests (which included the Hercules) due to pass through the South Atlantic in an attempt to secure their safety.

[5] Both bombs failed to detonate; one struck the foredeck and rolled into the sea and the other penetrated the deck and lodged in an oil tank, below the waterline.

[5][3] The deck and hull suffered extensive damage from the bomb strikes and missiles, and the Hercules began taking on water, developing a 6-degree list.

[5] On 20 July 1982, she was towed from Guanabara Bay by the tug Smit Lloyd 3 and scuttled by opening her seacocks at a position 250 nautical miles (460 km; 290 mi) off the coast.

This was reversed in the United States Court of Appeals for the Second Circuit in 1987 on the basis that it came within the scope of the Foreign Sovereign Immunities Act, as it resulted from a violation of international law by "attacking a neutral ship in international waters, without proper cause for suspicion or investigation", had a direct impact on the United States, as it was to carry oil for use in that country, and its loss disrupted contractual payments due to be made in New York.