Sea Shepherd has carried out armed boardings of foreign-flag vessels in international waters, scuttled and sunk fishing boats engaged in illegal fishery operations, executed acts of sabotage against vessels in harbor, and conducted an intense propaganda effort against Japanese high seas whaling and the Canadian sealing industry in particular.
Sea Shepherd is much more militant than Greenpeace and is believed by some to be a classic ecoterrorist organization. Indeed, Sea Shepherd has referred to Greenpeace as "The Avon ladies of the environmental movement".
In the course of these operations Sea Shepherd associates have been threatened, taken prisoner, and tried for commission of crimes on the high seas including maritime piracy, often with little success. Paul Watson, the founder of the group, has been convicted of a felony for his chemical attack on an unarmed Cuban boat fishing legally off Canada in 1995. Watson is barred from entry to the nations of the Helsinki pact due to past terrorist activities and is presently wanted for attempted murder in Costa Rica.
Several nations including Japan have pressured the United States to declare Sea Shepherd a terrorist organization. Sea Shepherd and its clandestine Canadian subsidiary ORCA are listed as terrorist organizations by Canada. At present Sea Shepherd continues to be based in Malibu, California with operations worldwide.
Major operations include interdiction against whaling in Antarctic waters, patrols of the Galapagos Islands, and action against Candian seal hunters. Sea Shepherd operates two large patrol craft at this time and a host of smaller vessels.