Volunteers from Fenit RNLI spotted Ruari McSorely among the bottlenose dolphins in the sea near Castlegregory in County Kerry.
Mr McSorely, from the village of Park in Derry, previously became an unlikely internet star known as “Frostbit Boy”, when footage of his eccentric interview on a local news channel went viral.
The 24-year-old had first been reported missing at 8am on Sunday, August 22, after a walker found his clothes on a beach in Inch, Kerry.
He told the Irish Independent that he had been sitting on the beach when he made the spur-of-the-moment decision to swim to what he believed was Fenit Island.
“I just jumped in, and that was it,” he said. “I saw Fenit lighthouse out in the water, and I said, right I’m going towards it.
“I wouldn’t have got in to start with if I didn’t know I was going to be grand.”
He was eventually recused at 8:15pm - 12 hours after he began swimming - and taken to University Hospital Kerry in Tralee.
He was discharged on Wednesday, telling reporters he felt “100 per cent” after his ordeal, and that there was “no long-term damage.”
“The only thing was my kidneys needed to readjust, so there has been no serious harm. It was only a matter of going into the hospital to heat up a bit.
“Other than that, I was fine,” he added.
“You know, to be quite honest, the only thing that is stressing me out is everybody else is panicking about it.”
Mr McSorely explained how the pod of dolphins surrounded him as he swam.
“I saw these black tails in the water, and I wasn’t sure were they dolphins or sharks,” he said.
“I just thought to myself, maybe it wouldn’t have been the worst idea to have googled this before I jumped in, but they were just dolphins.
“They wouldn’t have done any harm to you. I’d no problem with them.
“They were just swimming around me. If anything, they may have helped me. It was definitely an experience.”
Conservationists have now identified the animals as being from a group of bottlenose dolphins that feed and breed in Scotland's Moray Firth.
One of the dolphins in the pod, known as Spirtle, has made headlines of her own in recent weeks.
She was one of a number of dolphins that got into difficulty in shallow waters off the Cromarty Firth throughout August.
Conservationists said Spirtle made a miraculous recovery since being badly sunburned while stranded on the mudflats earlier this month.
Last week it was also revealed that she had given birth to a healthy calf.
Commenting on the incident, the RNLI said: "At 20:30, the volunteer lifeboat crew with Fenit RNLI spotted a pod of dolphins and a head above the water about two-and-a-half miles off Castlegregory beach.
"The casualty was conscious and immediately recovered onto the lifeboat and brought Fenit Harbour to be taken to hospital."