The former captain of the Ady Gil goes for a boarding attempt and one of the Sea Shepherd vessels goes dead in the water.

Pete Bethune recounts his experience aboard the Japanese security vessel.

The Sea Shepherds depart on their 2010/2011 ant-whaling campaign with a new, fast interceptor vessel. Early on, they find two harpoon ships before the whaling fleet has killed a single whale. Could they be set up for their most successful campaign ever?

After engaging the harpoon ships using the small boat teams, Captain Paul Watson makes the call to abandon the harpoon ships and go in search of the factory vessel. After a few hours of sailing, the tables have turned — two harpoon ships begin tailing Sea Shepherd!

Tailed by a harpoon ship, the Steve Irwin enlists the help of the Sea Shepherds' new, fast interceptor ship in an attempt to break free. Meanwhile, the Bob Barker crew spots a large blip on their radar and believe it could be their ultimate target: the Nisshin Maru.

When damage happens to one of the small boats, and the Bob Barker is five hours away, the crew realizes that they will have to spend a night at sea. But the crew is wet and freezing already, and early symptoms of hypothermia begin to set in.

The Bob Barker desperately searches for their two small boat crews who were lost at sea in the aftermath of a daring mission. Meanwhile, the Gojira locates the whalers' refueling vessel and Locky plays a dangerous game of "chicken" with the massive ship.

New Zealand's Navy contacts the Steve Irwin to respond to an emergency distress signal where five crew members from a Norwegian sailboat have gone missing. Now the Sea Shepherds must risk their lives in a dangerous mission to find the missing mariners.

As the first leg of their campaign comes to a close, the Sea Shepherds battle physical and mental exhaustion, especially pilot Chris Aultman. Thanks to an anonymous tip, the Steve Irwin finally locates the whalers' factory ship, the Nisshin Maru.

The Bob Barker and Gojira launch an ambitious assault on the harpoon ship that has been following them and manage to completely disable the whaling vessel. Now free of its tail, the Barker continues searching for their ultimate target, the Nisshin Maru.

The Sea Shepherds finally locate the factory vessel after months of searching, but it promptly tries to evade the Gojira.

In the fourth-season finale, Watson claims a major victory after 30 years of fighting, while he and the crew reaffirm their commitment to stopping the whaling fleet.

The Sea Shepherds face a difficult 2013 campaign with the Brigitte Bardot and their helicopter unavailable. The fleet introduces a new ship, the Sam Simon. Former captain of the Steve Irwin, Paul Watson, is forced to step down due to an injunction preventing him from coming within 500 yards of Japanese whaling fleet. All four of the fleet's main ships feature a new captain, with Watson serving as an observer. The Steve Irwin remains to coordinate the operation. The Bob Barker is sent to search for the whaling fleet and finally locates the Nisshin Maru near the western edge of the whaling ground. However, they sit helplessly as the Japanese successfully kill and load a whale onto the factory ship. The Sam Simon is sent to search for the bunker ship Sun Laurel and finally locates it along with 2 Japanese whaling ships. They attempt to block the refueling, but fail when the rookie captain pulls away, not willing to risk his crew. After hunting, the Nisshin Maru turns east. Realizing that the factory ship is trying to also refuel, the Sea Shepherds send all their ships to interfere. 30 hours later, the ships prepare for the showdown. The 500-tons Bob Barker blocks the 5000-tons Nisshin Maru by parking right next to the Sun Laurel. The Japanese warns the Bob Barker to move but captain Peter Hammarstedt refuses to comply. The Nisshin Maru then pushes the Bob Barker with their bow, damaging the ship and causing it to list dangerously. After a standoff, the Nisshin Maru backs away while the Sun Laurel abandons the operation. Days later, the whaling fleet leaves for Japan with only 103 kills.

After months of frustration, Sea Shepherd finally find their target - the Nisshin Maru. Now, they must run an eight-mile gauntlet blocked by two harpoon ships aggressively defending their mother ship. The success of the campaign rides on this moment.

With three activists aboard the Japanese security vessel, Capt Paul Watson hopes the media frenzy will force the Shonan Maru 2 to back off. Meanwhile, the crew of the Steve Irwin are plunged into their most violent battle yet.

When a massive target is detected on their radar, Sea Shepherd sends out their new helicopter pilot to ID the mystery vessel. But as the helicopter reaches the limits of its fuel range, it abruptly disappears, crashing into radio silence.

The exhausted crew of the Brigitte Bardot scramble to evacuate the ailing vessel. And Captain Paul Watson goes on the offensive, sending a team to board the heavily armed security vessel: the Shonan Maru.

The Sea Shepherd's stealth boat, the Ady Gil, launches a sneak attack on the Japanese whaling reconnaissance vessel in an effort to break free of the tail and find the rest of the whaling fleet.

The Sea Shepherds have been relentlessly followed by the whaling reconnaissance vessel for two weeks. They find themselves in a full-on engagement on the high seas as Captain Paul Watson orders a massive butyric acid bottle attack on his nemesis.

As the Sea Shepherds approach the Nisshin Maru, they are suddenly surrounded by four whaling vessels. Suddenly, one of the Japanese vessels moves in dangerously close, and as the deck crew quickly braces themselves, the ships violently collide.

After nearly a month of searching, the Sea Shepherds have finally found their ultimate target: the world's only whale factory ship, the Nisshin Maru.

The Sea Shepherds refuse to be bullied by the Japanese fleet even though they're out numbered. The deckhands repel over the side of the ship to assess the damage from the collision and realize that there is a gash in the steel hull and water is pouring in.

The Sea Shepherds' scout vessel, the Brigitte Bardot is damaged by a 30-foot wave, and help is more than 20 hours away.

The Yushin Maru No.3 has just collided with the Bob Barker (for the second time in almost exactly four years, the first time being during Operation Waltzing Matilda on February 6th, 2010). Crew rush below check the damage, which they find is just badly bent steel ribs, but no water entering the hull. As the Steve Irwin and Bob Barker race towards the Nisshin Maru's last known coordinates, the Sea Shepherds send video of the collision to the media. From his undisclosed location, Captain Paul Watson watches what happened on his laptop. He admits that the whalers more becoming more aggressive because they see that their days are numbered and also worried about the case brought against them in the International Court of Justice. Back in the Antarctic, the Nisshin Maru run into a storm to hide from the Sea Shepherds. Captain Peter calls Captain Sid to send the helicopter out, which does find the factory ship turning due east. The Bob Barker turns to intercept and soon finds the Nisshin within three hours. The harpoon ships are also there, but they don't turn to defend their mothership. Instead, the whalers wait until nightfall to engage the Barker. Both small boats (Gemini and Hunter) are lowered into the water and engage two of the harpoon ships (Yushin Maru and Yushin Maru No.3). They first try to cut the steel cables the Yushins are towing to prop foul the Barker, but don't succeed. So they drop prop foulers of their own to buy time. Soon the Nisshin slips away off the Barker's radar and Peter calls for the boats to return to the ship. As Operation Relentless comes to a close, the Sea Shepherds head back to port. On March 31st, 2014, the International Court of Justice (ICJ) ruled that the Japan's Antarctic whale research program (JARPA II) was not for scientific research and that their operations are illegal. After ten years of fighting, the Sea Shepherds celebrate their greatest victory to date. The whalers this season only killed 271 whales, falling 784 short of their total quota of 1,035. Captain Paul Watson was happy with the ICJ's decision and learned that Japan said it would abide by the ruling. But Paul is convinced that the Japanese whalers want their revenge and will do everything they can to keep going down to Antarctica to kill whales. He made clear if the whalers ever return, Sea Shepherd will be there to stop them. The following year (2014-2015), Japan sent two of its whaling ships on a non-lethal survey in the Southern Ocean Whale Sanctuary. Sea Shepherd admitted the whalers were planning ahead to return to killing whales. The whalers released a new program called NEWREP-A, which calls for the killing of 333 minke whales (no more fin whales or humpback whales will be killed) every year for the next 12 years (until 2027-2028). In 2015-2016, as Sea Shepherd conducted other campaigns around the world, the whalers did return and killed 333 minke whales (103 male and 230 female, 90% of the females were pregnant). Sea Shepherd announced the construction of a brand-new interceptor vessel they named Ocean Warrior due to be completed by September 2016. Most likely it will be sent to the Antarctic to confront the Japanese whaling fleet for the 2016-2017 whaling season. No announcements have been made if the Steve Irwin, Bob Barker, Brigitte Bardot, or Sam Simon will return to battle the whalers.

Without negotiation and confrontation with the MV Steve Irwin, the Yushin Maru № 2 agreed to transfer Pottsy and Giles to a government ship that would then meet with the Steve Irwin at a rendezvous point to return the two members. 1st Mate Peter Brown decides to launch an attack on the Yushin Maru № 2 at dusk. Four crewmembers are sent on the Zodiac inflatable boat Delta to carry out the risky mission. After losing radio contact with them, recon pilot Chris Aultman, who was sent too late to survey the situation, reports that they are heading in the wrong direction and must return as night falls. The lone Delta was feared to be forever lost out in the middle of the dark, frigid, vast Antarctic Ocean. Fortunately, contact was finally made with the Delta, which eventually returns to the MV Steve Irwin over two hours later and behind schedule to retrieve Pottsy and Giles.