Fran Murphy, 52, was paddling with friends on a sandbank at a resort near Perpignan when it collapsed, leaving her unconscious.
The group was saved by a man from Swansea, and Ms Murphy appealed on BBC Wales for help to try and trace him.
Now, she has met Ian Hullin and said it felt "wonderful" to be able to thank him for saving her life.
Ms Murphy, a Cardiff librarian, was with three colleagues when the incident happened earlier this month.
She was left unconscious and the group was unable to get ashore because of a rip current.
They were saved by a mystery man who got them ashore and then "disappeared".
Ms Murphy said her lungs were 80% full of water and she remained in hospital for over a week, with two days in intensive care.
She did not remember her rescuer but her friends believed he was from Swansea.
They said he joked that if he had known they were from Cardiff he would have "left them" in the water.
Ms Murphy had said she just wanted to thank him for the "amazing thing" he had done.
On Thursday Ms Murphy, her friends and Mr Hullin were finally reunited at her Cardiff home, and BBC Wales filmed the meeting.
She told him: "I'm just so glad that we managed to track you down so that we could just say thank you.
"You were just a mystery man to us at the time. We called you Mr Swansea.
"What you did was absolutely amazing. It might not be anything to you, but it meant a lot to us."
Mr Hullin said he was "really glad I could help", and told Ms Murphy: "You look better than the last time."
He also said his mother, from Cardiff, was "not happy" at his joke about leaving them if he had known where they were from.
He said he had made the joke while trying to reach shore with the second group of friends and was "running out of banter".
Ms Murphy said she was "absolutely ecstatic" to meet Mr Hullin, adding: "We're very grateful to the BBC. I don't think we would have found him otherwise."
Mr Hullin, who works in the protection of vessels as they pass Somalia, came forward after a friend of his partner's saw the story on BBC Wales Today.
His partner, Lucy Ross, said she had been having a "lovely sunbathe" when she noticed Mr Hullin had gone.
She assumed he had gone for a long swim, but said: "He just came back and casually said that he'd saved some women and then he just sat down."
She said her partner then "casually got on with his book".
For more on this story, see BBC Wales Today, BBC One Wales, at 18:30 BST on Thursday.

Prof Trevor Purt was suspended from Betsi Cadwaladr University Health Board (BCUHB) after it was put into special measures.
BCUHB ran the much-criticised Tawel Fan ward at Glan Clwyd Hospital, Denbighshire, which closed in 2013.
A health and care union boss said the move would "do nothing" to address "deep-seated" problems at the board.
Jon Restell, chief executive of the Managers in Partnership (MiP) union, said: "This will only create more instability, which is not in the patients' interests."
A report found there was "institutional abuse" at the Tawel Fan mental health unit, where patients were allegedly treated like animals in a zoo.
Deputy chief executive of the Welsh NHS Simon Dean was appointed as interim head of the board on Tuesday.

Gerald Jacob's family said he had retired last December and had been planning to "continue his life travelling" with partner.
The incident at Loggerheads is believed to have happened on Saturday at 19:30 GMT. Police were alerted to the crash scene on Sunday just before midday.
"Gerry, as we all knew him, loved life and lived it to the full," they said.
North Wales Police are appealing for witnesses to the incident on Ruthin Road involving a grey BMW car which was found in a hedge.
A Cardiff holidaymaker has been reunited with the mystery man who saved her from drowning off a French beach.
[NEXT_CONCEPT]
The suspension of the chief executive of a troubled health board is "short-sighted", a union boss has said.
[NEXT_CONCEPT]
A family has paid tribute to a "very special" 66-year-old man who died in a crash near Mold, Flintshire.