A flotilla of boats, including a former anti-nuclear warhorse, left Auckland yesterday to protest against deep sea oil activities of Brazilian multinational Petrobras.

The New Zealand Government granted Petrobras an exploratory licence last year for the Raukumara Basin which lies off East Cape/Cape Runway. Groups such as the Nuclear-Free Flotilla, Forest & Bird, 350 Aotearoa and Te Whanau a Apanui, expect seismic surveying to begin shortly.

A couple of hundred wellwishers waved off nine boats which will make their way down the coast by next Saturday, including the Vega from Princes Wharf.

Once owned by Greenpeace, the 12m Kauri ketch was boarded and detained by the French when it led protests against nuclear testing at Mururoa in the 1980s.

Daniel Mares, captain of Vega, said it was fitting one of the dames of environmentalism was getting a run in her own backyard about an issue he said was massively important.

"It's a short-sighted decision [to allow exploration to occur] and for what? The last drops of oil?"

Greenpeace climate spokesman Steve Abel said BP's Gulf of Mexico disaster showed the risk of deep sea oil drilling.

"A drastic spill would cost the New Zealand economy billions, and do enormous damage to our tourism and fishing industries, and our international reputation," Mr Abel said.

Peter Williams, QC, told the crowd foreign companies shouldn't be allowed to come here and "steal our oil".

Energy & Resources acting minister Hekia Parata said there was "scaremongering" going on that seismic monitoring could cause earthquakes. That "completely irresponsible" claim was made by anti-drilling group Te Ahi Kaa.

"There's no scientific evidence and it's wrong to be frightening people with that, " she said.