PORTLAND, Maine — Located in the South Pacific, hundreds of miles from its nearest neighbor, New Zealand has a long history of peaceful protest — particularly at sea. And the country’s Bill of Rights guarantees freedom of speech and peaceful assembly.

But earlier this year, multinational oil companies convinced lawmakers to restrict seaborne demonstrators who oppose oil drilling surrounding the island nation.

This week, the law is likely to get its first big test as the two sides approach direct confrontation.

A six-boat “Oil Free Seas Flotilla,” is sailing to stop deep-sea drilling 120 miles off some of New Zealand’s most iconic surfing beaches, Piha and Raglan. On Nov. 16 the vessels arrived at the site where Texas oil giant Anadarko was about to sink an exploratory well into the ocean floor 5,000 feet below the surface of the Tasman Sea.

The drilling ship Noble Bob Douglas arrived three days later and immediately declared, via radio, that the controversial new law applied, requiring the boats to stay 500 meters (1,640 feet) away from the drill rig. The flotilla responded that its boats would not comply. It has regularly radioed the Noble Bob Douglas with requests to leave New Zealand waters.

The oil-friendly law is opposed by figures as prominent as former Prime Minister Sir Geoffrey Palmer, a legal scholar, as an unlawful limit on the rights of free navigation and free speech.

It also defies historical precedent in enviro-friendly New Zealand, which once sent its navy to protect protesters at sea.

In the late 19th century, long before Mahatma Gandhi wielded nonviolence against Britain, native Maori people at Parihaka sent dancing children to face English soldiers attempting colonization.

In the 1970s and 1980s, private boats crossed the South Pacific to protest nuclear testing in French Polynesia. Closer to home, vessels blockaded Auckland Harbor against nuclear-powered US Navy ships.

This time around, leading the anti-drilling flotilla is the Vega, a 38-foot vessel that pioneered seaborne nuclear-testing protests and helped make New Zealand a nuclear-free nation. Vega is co-captained by the head of Greenpeace New Zealand, Bunny McDiarmid. Each boat in the flotilla is flying a white Parihaka pennant representing “peace, justice, resistance, and solidarity,” according to an accompanying letter from community elders.

The controversial law that Anadarko has invoked to repel the flotilla was hurriedly passed by the New Zealand Parliament after significant, and secretive, lobbying of government ministers by the oil industry. Allowing boarding and takeover of private boats by police, it is seen as a response by the conservative government to protests against a 2011 offshore expedition by Brazilian oil giant Petrobras, which soon thereafter scrapped all its New Zealand drilling plans.

Since the radio warning, the 38-foot-long Vega has stayed about 800 to 1,000 feet from the 756-foot Noble Bob Douglas. At times, according to Anadarko New Zealand manager Alan Seay, they have been within 330 feet of each other. The Vega is operating primarily under sail. To remain that close, it must tack about every eight minutes, according to Anna Horne, a flotilla spokeswoman who has sailed on the Vega to protest nukes.

According to Prime Minister John Key, drilling began early Tuesday morning, Nov. 26. Nonetheless, the Vega has remained within the exclusion zone.

Steve Abel, a Greenpeace New Zealand campaigner, says there has not been any sign of any authorities, nor any word from them. During the Petrobras protest two years ago, police arrived aboard navy vessels.

The protesters object to the environmental danger. New Zealand’s current ocean-drilling industry operates in very shallow waters. The deepest is about 400 feet. The country’s three small spill-response boats are not ready for operations beyond sight of land, they contend. “We are woefully underprepared,” Abel said.

Seay admits that the rig’s safety procedures have not yet been made public. That is to happen “shortly,” he said, noting that there is an “enormous amount of design and planning work that goes in up front to ensure that we have a safe and incident-free operation.”

The risk may be statistically low, but if a spill or blowout occurs, the damage will be “catastrophic,” Abel said, covering the entire west coast of the North Island within weeks, according to models of the spill. It would threaten tourism, fishing, and agriculture — all vital sectors of the New Zealand economy.

Abel also noted that the Deepwater Horizon blowout in 2010 in the Gulf of Mexico was also in roughly 5,000 feet of water — and that Anadarko was involved in that disaster, ultimately paying $4 billion as part of the legal settlements of that cleanup. “It’s the same company, the same depth,” Abel said. Anadarko is one of the world’s largest publicly traded oil and gas exploration corporations.

Sharing those concerns, more than 5,000 protesters thronged the western beaches of New Zealand on Nov. 23. The demonstrations included a significant Maori presence. In fact, the Tainui tribe may issue a legal trespass notice to the Noble Bob Douglas, which is in their traditional fishing waters.

“In many ways, [the Maori] hold the last line,” said Horne, noting not only their moral and cultural tradition of “kaitiakitanga,” or guardianship, but also their legal rights to many natural resources under the 1840 Treaty of Waitangi, which shares sovereignty between the Crown and the Maori.

The 70-day drilling project was slated to begin Monday, but unspecified technical problems caused delays. Anadarko will leave enforcement of the exclusion zone to New Zealand authorities. Seay said “we respect the right to protest but ask in return that protesters respect our right to carry on our business free of interference.”

But the protesters have no desire for the oil giant to operate unobstructed.

New Zealand could be oil-free, and even the world’s first carbon-neutral nation, Abel said. The country already is home to the world’s biggest geothermal plant, Ngatamariki in the central North Island. It also has a strong forestry industry, whose byproducts could be used in place of petroleum derivatives, Abel said. “For us it’s not a hard ask” to get off fossil fuels.

In fact, Abel noted drily, “None of this oil, if it’s found, will ever land in New Zealand — unless there’s a spill.”

Jeff Inglis is managing editor of the Portland Phoenix. During the past 15 years, he has traveled extensively in New Zealand.