Epic Chase Ends: Thunder Rolls

After a record-breaking 4-month pursuit by Sea Shepherd's ship Bob Barker, of the pirate vessel Thunder, which stretched from the Southern to the Indian to the Atlantic Ocean, the chase has ended in

dramatic circumstances.
On Easter Monday, the captain of Thunder sent out a Mayday call that his ship was taking on water. Bob Barker immediately moved in to assist.
When SS's Chief Engineer boarded Thunder in the hours leading up to the sinking, he saw clear evidence that the vessel was intentionally scuttled. Usually when a vessel is sinking, the captain will close all hatches so as to maintain buoyancy. However, on Thunder, the reverse was done - doors and hatches were tied open and the fishhold was opened.
SS's Bob Barker and Sam Simon rescued all 40 crew, including the captain, officers, and deck crew, who were all able to disembark to liferafts from Thunder before it sank.

Thunder was the most notorious of six vessels (which Sea Shepherd dubbed the "Bandit 6") known to engage in Illegal, Unregulated, Unreported (IUU) fishing of vulnerable toothfish in the Southern Ocean.
On Xmas Day 2014, Sam Simon commenced retrieval operations to remove the illegal fishing gear abandoned by Thunder when it first fled from Bob Barker. More than 72kms of illegal gillnet were recovered over a 3wk period, and over 1,400 fish (a total of 45,000kgs) were returned to the ocean.
In March, two more of the "Bandit 6", Viking and Kunlun, were detained by authorities in South East Asia, and their captains arrested.
The poaching vessels were the target of Operation Icefish, SS's Southern Ocean Defence Campaign targeting IUU fishing operators in the waters of Antarctica.

UPDATE: 12 October 2015 - final victory over Thunder.