The Thunder was one of six vessels known to be involved in IUU fishing for Antarctic and Patagonian toothfish in the Southern Ocean. The vessels, which Sea Shepherd calls the “Bandit 6,” were the focus of the organization’s 11th Southern Ocean Defense Campaign, Operation Icefish.

At the time it sank, the Thunder had been the target of a 110-day, record-breaking continuous pursuit by the Sea Shepherd ship, the Bob Barker. Sea Shepherd has consistently maintained that the Thunder was intentionally scuttled in an effort to hide its cargo of vulnerable toothfish, illegally caught in a region managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).

Since 2006, the Thunder has been on the IUU vessel list of CCAMLR and was blacklisted from fishing in the CCAMLR regulated area. In 2013, the vessel also became the subject of an Interpol Purple Notice for suspected illegal fishing activity following a joint effort by New Zealand, Australian and Norwegian authorities

The Bob Barker, Captained by Peter Hammarstedt of Sweden, and fellow Sea Shepherd ship, Sam Simon, Captained by Sid Chakravarty of India, rescued the Thunder’s entire crew of 40, who all disembarked to life rafts before the vessel sank.

Before the Thunder was fully submerged, members of the Sea Shepherd crews were able to board the vessel and collect evidence from the sinking ship, including a frozen toothfish that was later handed over to police.

Sea Shepherd has played a keen role in delivering justice to the officers of the Thunder, ensuring that loopholes commonly used to avoid prosecution could not be exploited.