Nisshin Maru
In January 2010, the ship continued to hunt for the Japanese fleet. After the loss of in a collision with "Shonan Maru No.2", "Steve Irwin" met up with , with which she exchanged fuel, supplies, and crew. The ship then returned to Fremantle to restock, departing on January 30. In the meantime, "Bob Barker" had located the factory ship, "Nisshin Maru", and was tailing the ship. On February 8, "Steve Irwin" joined "Bob Barker" in pursuit of "Nisshin Maru". Once the two Sea Shepherd vessels had linked up, "Steve Irwin" took up position behind "Nisshin Maru" to obstruct the factory ships slipway and engaged her with water cannon. On February 15, Pete Bethune departed from "Steve Irwin" on a jet ski, boarding "Shōnan Maru 2". He was subsequently detained and later arrested by the Japan Coast Guard for trespassing. The two ships remained behind the whaler until "Steve Irwin" was forced to return to Australia on February 18, arriving in Hobart on March 6.