The three-year-old penguin slid down a purpose-made hydroslide on the side of Niwa research vessel Tangaroa into the ocean at 10.30am today.
Wellington Zoo manager Lisa Argilla, who along with Niwa staff helped Happy Feet onto the slide, said he needed some gentle encouragement to leave the refrigerated crate that had been his home for the last six days.
"He was a little bit apprehensive because it was obviously something he'd never seen before so he chose to not step out of the crate. But after a gentle tap he went out onto the ramp.
"Slid in backwards, went under for a few seconds and popped up again and looked at us. And then he just took off and dove, and went under and far far away. So it was pretty exciting. It was a great release," Dr Argilla said.
The vessel dropped Happy Feet off 79km north of Campbell Island, roughly 621km south of New Zealand.
The entire crew was on deck to say goodbye to the penguin, who was now making his way back to his penguin mates she said.
"He probably needs to go a little bit further south to catch up with a few penguin buddies and he'll stay in this area until about this time next year when it's time to start heading back to Antarctica to find a mate and start breeding."
Happy Feet was "pretty chilled out" and had been happily munching on hoki, unperturbed by the rough weather conditions since he set sail from Wellington on Monday, she said.
He was due to be released on Friday or yesterday but 40-50 knot winds and 6-8m swells kept the penguin on board the ship.
Voyage leader Richard O'Driscoll said the special passenger had been a good traveller.
"He's been a well-behaved passenger, except when our team have helped to feed him, and he's shown them who the boss is with a peck or two."
Happy Feet made headlines when he was discovered on Peka Peka beach on the Kapiti Coast in June. He was taken to Wellington Zoo where he underwent four operations to remove stones, sand, and other matter from his stomach.
Now back in the water, Happy Feet can be tracked on the Sirtrack and the Our Far South website as he has been fitted with a Sirtrack satellite tracker and a microchip.
The Tangaroa research team will now resume business as usual, and continue its month-long survey of Campbell Island southern blue whiting stocks.
