WELLINGTON, New Zealand — Free at last. The wayward emperor penguin dubbed "Happy Feet" is back in the ocean south of New Zealand.
The penguin was released from the research vessel Tangaroa on Sunday morning about 50 miles north of remote Campbell Island in water about 935 feet deep, about 430 miles south of New Zealand.
Wellington Zoo veterinarian Lisa Argilla said Happy Feet needed some "gentle encouragement" to leave the purpose-built crate that had been his home on the boat for six days.
Argilla said boat crew members at carried the penguin inside his custom-built crate to the stern of the ship for his final send-off. The crew had already cut the engines and put in place a canvas slide that they soaked with water from a hose.
But when they opened the door of the crate, the penguin showed no interest in leaving.
"I needed to give him a little a tap on his back," Argilla said.
The penguin slipped down the slide on his stomach, bum first, she said. He resurfaced about 6 feet from the boat, took a look up at the people aboard, and then disappeared beneath the surface.
"Once he hit the water he spared no time in diving off away from the boat and all those 'aliens' who have been looking after him for so long," Argilla said, according to a zoo statement.
"It's an indescribable feeling to see a patient finally set free! It’s definitely the best part of the job," Argilla said.Video: After rehab, lost penguin ‘Happy Feet’ returns to the wild (on this page)
The bird was discovered June 20 on Peka Peka beach on New Zealand's Kapiti Coast, about 1,800 miles from his Antarctic feeding grounds.
At first, conservation authorities said they would wait and let nature take its course with the penguin. But it soon became clear the bird's condition was deteriorating, as he scooped up beaks full of sand and swallowed, likely mistaking it for snow, which emperor penguins eat for its moisture when in Antarctica.
With the world watching, authorities finally took action, moving the penguin to the Wellington Zoo four days after he was discovered.
At the zoo, the 3 1/2-year-old bird underwent numerous stomach flushing procedures to remove sand from his digestive system. He was given a makeshift home in a room that zoo staff kept filled with a bed of ice so he wouldn't overheat.
A local television station, TV3, set up a Web cam and streamed images of the bird around-the-clock. Soon, Happy Feet had a quarter-million followers.
Onboard Tangaroa, Happy Feet was treated to hoki for his meals and fresh ice put in his crate each day, zoo officials said.
Happy Feet has been fitted with a Sirtrack satellite tracker and a microchip, thanks to the generous support of Gareth Morgan, the zoo said. Fans can follow his progress at www.nzemperor.com/.
The Associated Press contributed to this report.