To the west, a Danish frigate shadows his 650-ton all-black vessel with its giant skull-and crossbones flag. Two coastguard vessels lurk out of sight. Military helicopters have been buzzing overhead. A long game of sea chess is starting over the right to kill or to save pilot whales.

Captain Paul Watson, founder of the Sea Shepherd Conservation Society, stands on board his ship, the Ocean Warrior, Friday July 7, 2000, in Torshavn, the Faroe Islands in the North Atlantic Sea. Watson and other members of the society are trying to stop the traditional pilot whale hunting in the waters around the Faroe Islands, which is part of the state community with Denmark and Greenland. (AP photo/Jens Kristen Vang)

Watson is calm, eager to talk about everything from religion to philosophy. He quotes films, reads widely, laughs a lot. In 1986 he came to the Faroes to stop the islanders quite legally killing whales - something these Danish, but self-governing islands have done for centuries. He missed a "grind" (or hunt) by minutes. "I'll never forget the blood stains, the screams of tortured whales. We witnessed a depraved act of senseless violence", he says. The Faroese chucked tear gas and opened fire, just missing Watson. He retaliated by firing a cannon filled with chocolate pudding and vowed to return.

This month he plans to halt what he calls "the largest and cruellest sport hunt in the world" and will spend weeks patrolling the islands, trying to head whales off into the ocean and stopping "once and for all" the slaughter of whole families of pilots which the islanders herd into bays to drag ashore and kill with knives up to 10 times a year.

"They butcher adults, juveniles, pregnant females and foetuses, entire pods (groups)" says Watson. "This is the 21st century. Barbaric traditions do not belong here, especially in a society with one of the highest standards of living in Europe. He reckons he was once saved by a dying, harpooned whale. "I looked into its knowing, kind eye, and it chose not to kill me."

No country doubts he can cause mayhem. In 23 years Watson and members of Sea Shepherd, the Vancouver-based group he founded in 1977, have rammed and sank whaling ships, interposed themselves between whales and harpoonists and fought with sealers, loggers and hunters. They have slammed boats into Japanese trawlers and been attacked by Russians, Norwegian, Icelandic and Japanese governments and companies. "We are a kick-ass organisation. Our purpose is enforcement, not protest," he says. "The real terrorists are those who destroy the earth."

Watson, who teaches ecology and ethics at California universities, is a lifelong rebel. A "biocentrist", who believes the life of a whale or a dolphin or any other wild animal is of equal value to that of a human, he is a carnivore on the basis, he says, that it is acceptable to eat animals reared for human consumption. He loves the freedom of the seas and solitude, to "swim at night alone in the deep, living oceans". He passionately believes in humanity but no more or less so, he says, than he does for any of the world's 35 million other species. His crusade is simple: to redress the human relationship with nature. "Even if all the world were in favour of whaling I would try to stop it," he says

To board Ocean Warrior is to accept the dictatorship of this latterday Captain Ahab. He may believe in democracy ashore but he accepts no "concensus shit" at sea. He abides no drugs, or "friggin in the riggin", takes no advice, gives no clues to his plans and calls himself a "humble fanatic". He acts by a Zen-like martial code culled from ancient eastern and modern western warfare methods and expects to die for his cause. Miraculously, no one has been injured in his confrontations.

It's been a long trip to the Faroes, physically from the US west coast and metaphorically from the 1970s when, as a founder member of the group that became Greenpeace, he sailed to the Aleutians to stop an H-bomb test. Since then he has fallen out mightily with Greenpeace ("the Avon ladies of the environment") and just about every other conservationist. He despises their methods, their politics and their self-serving agendas. His campaigns - costing less than $1m (£666,000) a year - are financed by Sea Shepherd's 45,000 members and individual gifts from rich Hollywood and Las Vegas supporters. Next month a $50m film based on his exploits will start shooting. It will glorify him and surely attract more members.

"Watson is smarter now," says Bob Hunter, another Greenpeace co-founder aboard the Warrior, and the man who expelled him in 1976 for being too radical. "He was possessed by too powerful a drive to push himself front and centre," he remembers. "He's learnt. He's refined his tactics. He's getting more hard-line. He realises it will take hard-core effort."

Down in the galley, the 10-nation volunteer, mostly vegan and veggie ecological gunslingers of the 27 strong crew - sailors, adventurers, professors, surgeons, firemen, students and nurses, together with Watson's wife and playwright daughter - have been watching crappy movies and a recording of Black Harvest, a BBC documentary about the 1986 whale hunt. The atmosphere is relaxed. Relationships are developing. There's a poker game and whiskey. Theo and Hans, two Dutch stand-up comics, friends of one of the movie stars aboard, have provided entertainment.

Up on the bridge, Watson says he has nothing against the Faroese people, just their one bad habit. But he faces two problems. Firstly, there are no whales. In four days a lone minke has visited the ship. The pilots migrate to the Faroes to mate and feed off squid but none has been sighted near the islands for months. It could be, thinks Watson, because there has been overwhaling.

Secondly, the Faroese police have spent hours swarming over the boat, checking for firearms (none) and defences (three water cannon, rolls of barbed wire, grease and whale recordings to blast over the islands). Everyone aboard, except three European photo-journalists with UN-authorised press cards, are classed as "alien participates" of Watson and "assumed to be intending to use physical and possibly violent actions ... to violate Faroese law". My Guardian identification, calls to the police and consuls are insufficient. The penalty is prison, steep fines and deportation with no appeal.

Moreover, the police have also fined Watson £5,000 for entering Faroese waters and warned everyone that unless they take "active measures" to prevent him violating the law, we shall be held responsible. It is, says Watson, "incitement to mutiny" against maritime law.

The choices are clear. Mutiny and be arrested. Stay aboard and be arrested. Go ashore and be arrested.

Until the whales arrive, Watson has used different gambits, taunting, provoking, drawing out the enemy and using the media as a defence. In the past week he has both stuck to Faroese rules and ignored them. Now, on the spur of the moment, he has decided to return to the Shetlands, 16 hours away, to drop off some people and collect more before returning. The only way I will hear the Faroese side of the story is to meet them. I request permission to land.

But the game must go on. We have, illegally, headed up Vestmanna fjord and back to the capital Torshavn. Hundreds of people line the shore, watching the black ship's progress. The authorities do not react. At 9pm, outside the harbour, Watson sets adrift in rubber dinghies the two Dutch comedians and Frank Tringle, a former US army helicopter attack pilot who is now Sea Shepherd's communications officer. Watson guages - accurately - that the Faroese will pick them up. Two pawns and a rook, they are expendable. They will make a public statement against whaling which should boost Watson's media defence.

The Ocean Warrior heads on. We approach Westmanna village, the second-largest Faroese community in the midnight half-light. Watson's longstanding friend, the first mate Pete Brown, skims me three miles to the harbour in an inflatable dinghy. Within seconds of my climbing the dock's rubber fenders, he has shot back to the Warrior. I have walked 500 yards by the time two cars approach.

A window winds down. "You are from the Guardian?" "How did you know?" "I work for the local paper. Can I take your picture?" My plan, I say, is to talk to as many Faroese about whaling as quickly as possible in case I am arrested and immediately deported. So, if he can resist telling the police that I am here for a few hours I'd be grateful. We try to rouse the only hotel. We talk briefly to Else, a passer-by ("What's wrong with whaling? We need the meat".). We wake the local taxi driver who says he will take me to the capital. But within 15 minutes, four police arrive. They are delightful.

"I am sorry but you are under arrest. Well, no, you are being detained," says one. We drive to Torshaven. There is little crime on the islands, it seems. A few drugs, lots of minor traffic offences, perhaps one murder a decade. The chief drugs officer says Watson is a lunatic. A female officer takes my statement and makes her own: "I'd rather be killed as a whale than as a calf. We are in touch with what we eat. Watson lies but I don't get angry. It's 'spilt tid' [wasted time]", she says. She charges me with illegal entry.

And so at 4am, to the cells. A Faroese prison is quite like a British youth hostel but with good food, soft beds, TV and warders who will nip out and buy you fags. The Dutch stand-ups and Tringle have already been charged and are joking in bed. For company the next day we have a rapist, an alleged drugs dealer, a child molestor and a Dane of indeterminate guilt. None has a problem with the hunt.

"I love animals," says the woman on drugs charges. "I have a picture of me and my children sitting on a whale waving two knives, with a scarf saying 'psycho' on my head. We are the most Christian country, and just as you arrived, I was reading the Third Book of Moses, chapter 11, where it says whales are "dirty" animals and must not be eaten. Funny, isn't it?''

It is. Warders, prisoners and police are united. Watson is variously a "maniac", "disturbed", a "danger". The Faroese, it transpires, plan to stop him disrupting their grinds by placing their ships between him and the hunters. They also fear some people may be drunk in charge of their whaling knives. There could be human bloodshed too.

By the afternoon, the British consul, a newspaper editor and the Guardian have confirmed my identity and I am free. The first stop is Dr Paul Weihe, chief Faroese physician who has done years of research into the toxicity of whales and the health of Faroese children and shown how whales act as filters accumulating mercury and man-made PCB chemicals . If digested, especially by the foetus, he says, whale meat can affect the nervous system.

On his advice, the government advises pregnant women to eat no whale and says everyone should restrict their consumption to twice a month. The US Academy of Sciences now accepts his research and last week recommended that the US tightens its laws on industrial pollution that is poisoning the oceans. The intense reaction to Watson, he says, "is what you would expect from any tribe when threatened".

The next stop is Dr Dorete Bloch, the zoologist head of the national museum. "So little is known about where they come from or go to," she says. She believes they arrive in pods of families to meet and mate with other groups to preserve the gene pool. The north-east Atlantic population of more than 800,000, she says, is sustainable, the Faroese taking an average 950 a year, or less than 0.1 per cent of the total. Watson, she says, "should be sent for tests". Kate Sanderson, the prime minister's spokeswoman on marine affairs, dismisses Watson as "a dangerous distraction". Sea Shepherd, she says, "is a cult of marine mammal-rightists. There's no sense talking to them. We will only give up if the meat or blubber is too contaminated to eat [which it is not] or if the numbers are unsustainable [which they are not ]". She concedes that Watson's actions have led to improvements in how the whales are killed but denies that his campaign to get German consumers to boycott Faroese fish is having any effect. Politically, she says, the islands can thank Watson for unifying them.

Supper is with the community whaling group. Olavur Sjurdarberg is a headmaster. Hans Hermmmansen has been celebrating. Olavur has pre-ordered a meal. It starts with a full plate of best wind-dried , jet-black whale meat and white rubbery blubber. It is, they say, "a delicacy, a necessity and a pleasure". It's also a test of which side I am on. "How is it?" "... Whaley." "You like it?" "It's ... special." "Good?" "...Strong." Test over, they express their affinity with whales. "I love them. They are so elegant, a fantastic sight. It's the worst thing I know to kill an animal. We don't like the sound when we kill them. The only pleasure is doing it fast. But it is necessary", says Olavur.

Hans puts the whales' absence this year down to history which suggests they seldom come at the turn of centuries. "I have killed many, many whales. We have to kill them, but we are good killers. It's instinct. You need a very sharp knife. Look, [he demonstrates] three cuts, here, here and here. Three seconds, that's all it needs. In every culture a good killer is a good man." Soon he will teach his 18-year-old son to kill. He acknowledges the statistics showing it can take several minutes for a whale to die. "But most go in under 25 seconds..."

In the old days, says Olavur, the Faroese starved when whales did not come. They are a gift, he says, "fruits of the garden of the sea". The hunt is regulated, and the meat , he says, is given free to hospitals, old people, and everyone who wants it. "There are ballads and dances. No money changes hands. It is beautiful. When I am old, a child will bring me a bucket of the meat."

They say the Faroese saw films of the "grind" after Watson's 1986 visit and realised that they could kill more humanely. "It is better now", says Olavur, "perhaps it was barbaric then but not now. We need whale meat to save money, but also for our health. We would suffer badly in the winter without it." Never mind the warnings about mercury, Hans admits that he eats blubber all winter and that his pregnant daughter eats it too. "Why not? She has a right. There's nothing wrong with her," he says.

Olavur is, by now, practically kicking Hans under the table but it doesn't matter. Clearly, the Faroese love whales with a fervour equal to Watson's. Love them to death, even, and all the world's animal lovers will find it impossible to persuade them to halt something they believe is the tap root of their life. "Come back, stay with us, join the hunt, " says Hans.

"It is a clash of cultures. Let's say we live in opposite worlds," says Olavur.

© Guardian Newspapers Limited 2000

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