Michael Eavis first went to sea in 1951, when he was a 15-year-old farmer's son from an undistinguished village near Glastonbury. The death of his father four years later brought an end to his career as a sailor, however, and he returned to manage the dairy herd and, almost by accident years later, to found Europe's biggest music festival.
He has never lost his sea legs, however, and on Thursday the 76-year-old fulfilled a six-decade aspiration to take his place again behind the bridge of a ship.
That the vessel was the brand new Rainbow Warrior, the flagship ofGreenpeace which Eavis has long supported, was all the more fitting.
There was no call for his training to take sextant measurements, but a stint behind the wheel had him giggling like a schoolboy.
The ship, freshly launched from its German shipyard, is undergoing sea trials and so the first, Eavis-directed voyage (though the actual navigation was in the hands of the captain and a Thames river pilot) was a brief one, from West India Dock in London's east end to a mooring alongside the Design Museum on the South Bank.
"I'd love to take her under there," said the American captain Joel Stewart gesturing at Tower Bridge, "but that's a battle we would not win." Even with the bridge open, the ship's enormous 55m mast is more than 10m too tall to journey any further up the Thames.
This is the third Rainbow Warrior to sail under Greenpeace's livery – the first, notoriously, was sunk in New Zealand in 1985 by French commandos to prevent it hampering nuclear tests in a Polynesian atoll. The second has just been retired to Bangladesh, where it serves as a hospital ship.
Rainbow Warrior III is bigger, greener and, for the first time, purpose built, which the organisation says will showcase green shipbuilding technologies.
The huge A-frame mast system can carry considerably more sails than a conventional mast on a vessel of this size, meaning that the ship will travel, as far as possible, under wind power. Systems to recycle the engine's heat and waste "grey" water, and a hull designed to minimise friction in the water, add to its green credentials.
"The emissions from shipping are going up and are of increasing concern, so we have really got to think about how we can end our dependency on oil in this area," said John Sauven, Greenpeace's executive director. "This lets us provide a fantastic example.
"There are so many features of this boat that are state of the art. I like finding technological solutions to environmental problems."
Perhaps the most striking feature is a helipad worthy of the flashiest private yacht, though the organisation does not have a helicopter of its own. "If you're going up the Amazon to investigate deforestation, there are very few roads, so you need to have something like a helicopter to take aerial photos," said Sauven.
Not that much of the pad could be seen under a tangle of wires, amps and microphones, as a crew set up for a free on-deck performance by the band the Good, the Bad and the Queen, featuring Greenpeace supporters Damon Albarn and Paul Simonon, formerly of the Clash.
There was a brief ceremony in which Eavis unveiled a plaque in his honour, adorned with a quote of his own: "Live fast and live long" ("I don't remember saying that, but I'm sure I probably did. It's a good motto anyway").
Greenpeace has particular cause to honour Eavis, who was joined on board by Emily, his daughter and festival co-organiser, and her baby son George, as he donates £400,000 of the festival's income to the organisation.
Not all the crew had been fully briefed, however. "I run a festival, called Glastonbury," Eavis was later overheard telling Seychelle Colland, a 26-year-old Canadian volunteer. "I don't know what that is," she said. "Is it famous here?"
Twenty-six years after the original Rainbow Warrior was bombed, Greenpeace is still seen as a threat. In 2006 the French energy company EDF hired private detectives to hack into its computers to find out more about its campaigns against nuclear power in the UK.
As the ship pulled out of the dock mobile phones started ringing, to be answered by whoops – a French court had fined the company €1.5m (£1.3m) and jailed two executives for three years for their part in the spying operation.
Thirty minutes later the ship was docking by Tower Bridge when a river cruise boat sponsored by EDF energy passed, to good-natured cheers. It was followed by a French navy warship, the Lieutenant de Vaisseau le Henaff, its crew standing to attention while a tug pulled it past the Royal Navy pontoon.
Rainbow Warrior III sounded its horn.