Work in progress. Crew will sail down to Ensenada to complete fitting out.

Getting aboard is an act of recklessness in itself. The bouncy gangplank is not attached to anything. You edge your way over like a tightrope walker.

Men and women crisscross with paint brushes, drills, mysterious boxes. They’re transforming this ex-Navy WW2 tugboat into a chase boat for high seas eco-confrontations to come. They have stopped off in San Diego to pick up a valuable cargo, a military-grade UAV — unmanned aerial vehicle. Drone. Worth $4 million, maybe more. It’ll be their eyes and ears when they go operational at points from Mexico to Antarctica. Think Sea Shepherd, think Greenpeace. This is Earthrace.

All it needs is its rotors. Jesse Neushul and the brand new drone, by Schiebel of Austria

“Here, I’ll show you,” says this blond-haired kid in shorts. Well, not kid. He’s 21, Jesse Neushul, the ship’s only San Diegan. The rest are international volunteers. Neushul’s volunteering aboard during his vacation from UC Santa Barbara, where he’s studying environmental politics.

Pete Bethune, the captain and leader, appears. Also in shorts. His upper body is tattooed Maori-style. He is a Kiwi, famous in eco-circles for having created a legendary biofueled speed boat, Earthracer, that ran on used domestic vegetable oils. In 2004, to prove it, he sped around the world in a record 60 days, 23 hours and 49 minutes, a circumnavigation two weeks faster than any human before or since.

Since then he has created Earthrace Conservation Leadership. “We do missions to save our planet,” he says. It’s front-line action stuff, from secretly invading a de Beers diamond mine in Namibia to expose the annual clubbing of baby seals, to arresting seven boats hunting threatened species around Cocos Island off Costa Rica.

Captain Pete Bethune shows his moko - Maori tattoo - showing his whakapapa - genealogy - through symbols

“We could arrest them because we operate a little differently from other activists like Greenpeace or Sea Shepherd. We work with the host governments to help them police their waters, and they send officers with us, so it is them arresting,” says Bethune.

They have been shooting a reality TV show documenting their work, using ex-special forces guys to find and stop bad actors illegally fishing, poaching, destroying habitat, gold mining, wildlife smuggling. The show, The Operatives, has been aired by the Discovery Channel, Pivot, and other outlets. But in the Antarctic, a Japanese whaling security boat charged and sank Captain Bethune’s boat. They arrested Bethune, and sent him to maximum security prison in Japan for five months.

“But that may have been our best moment,” he says, “because international outrage caused nations to turn against Japanese illegal whaling in Antarctica.”

So Modoc, this solid, stolid tug, is the replacement for Earthrace, which had been called the sexiest boat afloat? “Sure. Now we don’t need speed. We have this magic tool,” Bethune says. “Our beautiful eye in the sky.”

Captain Pete Bethune and his adopted pet, Ankar

San Diego’s volunteer Neushul takes me to the upper deck, where among all the boxes and bits of gear, this shining torpedo-shaped thing sits glinting in the sun. This mini-helicopter, like a millionaire’s toy. Their own UAV.

You can see Jesse is in love with this change in his life. “Studying environmental politics is all very interesting,” he says. “But this is direct and immediate, on the edge of legitimacy.”

Captain Bethune says they are always looking for volunteers. “It’s no pay and hard work,” he warns. “We don’t have time for slackers.”