For someone whose CV includes sinking whaling ships and obstructing club-wielding Canadian sealers, Paul Watson remains remarkably placid.
The soft-spoken conservationist, who for the past month has been harrying Japanese whalers in the Southern Ocean, is quite simply in his element.
If Governments such as New Zealand and Australia that claim Antarctic territory won't intervene against whaling in a whale sanctuary, Watson says, then he and his Sea Shepherd Conservation Society are prepared to try.
He will order the whaling fleet's seven ships to leave the area, citing the UN World Charter for Nature, under which individuals and organisations are empowered to safeguard and conserve nature in areas beyond national jurisdiction.
If that doesn't work, his 30-year record of direct action shows he has plenty of other ideas.
"When critics say we are going too far, our answer is that, for the whales, things have already gone way too far," says the grey-bearded Canadian who rejects the label "terrorist" but doesn't mind "pirate".
During the past week, Watson's crew attempted to use steel cable to foul a whaling ship's propeller. They sideswiped the whalers' supply ship using their "can opener", a steel blade designed to inflict maximum damage to a ship's hull.
He says he's not the only one playing hard, accusing a Japanese captain of trying to run down his much smaller vessel on Christmas Day.
Watson says his tactics work. He reckons whalers flee whenever he arrives on the scene and as long as they're not whaling that's good enough for him.
But the willingness to get physical leaves some people uneasy. On Wednesday Conservation Minister Chris Carter labelled Watson's sideswipe attack "very irresponsible" and said it was contributing to the whalers' "increasing anxiety".
Late last month, Carter's Australian counterpart, Ian Campbell, attacked what he called a "war-like" statement by Watson that he was willing to lose his ship to stop the whalers.
"The word deranged came to mind when I read it," Campbell said.
Watson took it in stride, describing as "contemptible" the decisions by New Zealand and Australia not to send warships to the region.
"I think they're kissing the rear ends of Japan."
He dared Campbell to have him arrested and accused the minister of being more concerned about trade with Japan than about the possible deaths of almost 1000 whales.
Property damage is not really violence, Watson says. Violence, he insists, is inflicting harm on a living creature, something he says has never happened in his campaigns.
Watson has been defending animals since he was a boy growing up on Canada's Atlantic coast. When he was 10 he joined the Kindness Club, a group that encouraged children to protect animals. He promptly set off into the bush destroying leg-hold traps.
Watson left home at 16. Within a year he had become a merchant seaman travelling the world.
In the early 1970s he helped found Greenpeace but grew frustrated with what he saw as a softening of the group's values and a growing bureaucracy.
He founded Sea Shepherd in 1977, and the group continues to revolve around him. It is, he says, "like being a soldier in a war that never ends".
"We survive because we have the audacity to believe that we matter," he mused last month.
In a less pensive mood, Watson shows off his flagship and breaks into a grin while swivelling his high calibre "goo gun". It's powered by compressed air, and for ammunition there are cases of pie filling.
When it's time to psych the crew for action, he reaches for his CD of Wagner's Ride of the Valkyries and lets the music soar through huge loudspeakers above the wheelhouse.
Watson's campaign tally since 1977 includes eight whaling ships sunk, in port, either by known Sea Shepherd operatives or by others whom he prefers to describe as "allies". There have been no injuries, a record he says he's dedicated to maintaining.
He shares his love of the oceans with Allison Lance Watson, whom he married in 2001, and who is one of the 43 crew with him on the ship Farley Mowat. Their home is on an island in the US state of Washington.
His 25-year-old daughter from his first marriage, Lilliolani, occasionally joins her father at sea.
This is Watson's 194th ocean trip in command of his own ship and, having just turned 55, he shows no sign of easing up. On his birthday last month, he did, however, indulge in some introspection.
"In truth I feel much younger," he said. "My spirit still yearns for adventure, and my intense burning anger at the state we have driven our world into is as hot as when I was half this age."
Animal rights versus green terrorism
Paul Watson summed up his approach at an animal rights convention in 2002, saying: "We should never feel like were going too far in breaking the law, because whatever laws you break to liberate animals or to protect the environment are very insignificant."
But his means-to-an-end have seen him described as one of the "fathers of environmental terrorism" by food industry website ActivistCash.com.
And some former colleagues in Greenpeace have distanced themselves from Watson. Co-founder Jim Bohlen told the Los Angeles Times: "I've known the guy for 15 years and he's absolutely insane."
Watson's history is littered with controversy:
* At 10 years old, Watson shot another boy, who was about to shoot a bird, in the backside with a BB gun.
* He was arrested in 1993 in Canada on charges stemming from actions against Cuban and Spanish fishing boats off Newfoundland, but was acquitted by a jury.
* In 1997, he was convicted in absentia by Norway on misdemeanour charges of sinking the small-scale Norwegian fishing vessel Nybrnna in 1992, but Dutch authorities refused to hand him over to Norwegian authorities. He spent at least 60 days in detention in the Netherlands before being released.
* Costa Rica filed attempted murder charges against Watson for an incident when he caught a Costa Rican fishing boat poaching, but charges were dropped after prosecutors were shown a film of the incident that was shot by a documentary team.
* When Watson was in Auckland in 2002, police searched his ship for torpedoes. None was found.
* Neil Sanderson is editor of the Herald website. In 1981, he sailed with Paul Watson to Siberia, where they documented illicit Soviet whaling.