As the boats from New Zealand, Australia and Pacific island nations, together with the Greenpeace protest vessel Rainbow Warrior II, took to the seas, politicians and anti-nuclear activists from the Pacific, Europe and Japan were preparing to gather in Papeete for demonstrations next weekend.
Their protests are likely to be ignored by the French government. If Paris sticks to its declared timetable, then some time after midnight on Friday 1 September, a nuclear device in a shaft drilled under the lagoon at Mururoa will explode with enough power to cause a small earthquake.
This will be the first of seven or eight nuclear tests planned to be conducted between September and May. Greenpeace has said that Rainbow Warrior II and other craft will try to breach the 12-mile military exclusion zone around Mururoa. Philippe Euverte, the French naval commander in the South Pacific, said that the tests would go ahead regardless of whether protest ships were inside the lagoon.
The French navy frigate Prairial was reportedly tailing the Rainbow Warrior II yesterday, at a distance of about two miles.
In Australia, five anti-nuclear protesters were arrested when they landed inflatable craft outside the official residence of Paul Keating, the Prime Minister, on Sydney Harbour and unfurled a banner calling on the Australian government to send a protest ship to Mururoa.
Since Mr Chirac announced the testing programme on 13 June, it has sparked one of the biggest anti-nuclear and anti-French protest movements the Pacific has seen. Demonstrations and boycotts of French products in Australia and New Zealand have been followed by personal abuse against French people living in both countries. French relations with Canberra and Wellington have plummeted.
Mr Chirac has badly underestimated the strength of opposition in the Pacific. Since the French began testing nuclear weapons in the Pacific in 1966, the region has grown increasingly outraged at their actions. The first 41 tests at Mururoa and neighbouring Fangataufa atoll were in the atmosphere: France has never signed the Partial Test-Ban Treaty of 1963, under which Britain, the US and the then Soviet Union agreed to end atmospheric testing.
Concern over French intransigence provided a fillip for the formation in 1971 of the South Pacific Forum. Then, many island nations were colonial dependencies of Britain, Australia and New Zealand. Now, France is the last major European colonial power in the Pacific, and the forum has become an established body of 15 independent nations whose largest members, Australia and New Zealand, have developed a close regional identity with their island neighbours.
France switched its Pacific tests underground in 1975 only after Australia and New Zealand had launched action in the International Court of Justice calling for an end to atmospheric testing. Up to 1992, when Francois Mitterrand, the former president, declared a test moratorium, the French conducted 139 underground tests at the two coral atolls. That moratorium, together with the end of the Cold War and moves towards a Comprehensive Test Ban Treaty, created a belief in the Pacific that the bad old days were finally over.
That hope was shattered on 13 June. The outcry since then appears to have shaken the French. They have declared that, after May, they will be in a position to conduct future tests by computer simulation. In any case, they argue, Mururoa - 625 miles south-east of Tahiti - is one of the world's most remote locations, where testing is unlikely to harm anyone.
The Pacific countries retort that this is typical French arrogance. After almost 30 years of testing in their territory, many Polynesians have been driven to demand independence from France.
A report by 20 leading Australian scientists, presented to South Pacific Forum environment ministers 10 days ago, said: "The French tests, which are conducted between 600 and 1,200 metres underground in volcanic rock, by their very nature result in localised fracturing of the rock around each test site ... More significant is the risk of long-term leakage of the longer-lived radio-isotopes into the lagoon and surrounding ocean."