Cuomo, 45, said: "There's a guy who gets caught in a rip current off the coast of New York's Long Island and guess who's there to save him -- this guy."
He threw the man a life preserver but it wasn't enough to rescue the person in the water.
He said: "So I didn't think. I went in and got him. It was hard for us to swim across but we eventually did."
New York Post's Page Six initially broke the news on Monday.
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CNN anchor Chris Cuomo saves man from drowning in riptide: 'I didn't think, I just went in'
NEW YORK, NY - MAY 17: Chris Cuomo attends the 2017 Turner Upfront at Madison Square Garden on May 17, 2017 in New York City. (Photo by Daniel Zuchnik/WireImage)
NEW YORK, NY - MAY 28: Chris Cuomo attends the 2015 HELP USA's Hero Awards Dinner at Cipriani 42nd Street on May 28, 2015 in New York City. (Photo by Steve Mack/FilmMagic)
NEW YORK, NY - MAY 12: New York Governor Andrew Cuomo and Chris Cuomo attend The Robin Hood Foundation's 2015 Benefit at Jacob Javitz Center on May 12, 2015 in New York City. (Photo by Kevin Mazur/Getty Images)
NEW YORK, NY - NOVEMBER 18: Chris Cuomo attends the 2014 CNN Heroes: An All Star Tribute at American Museum of Natural History on November 18, 2014 in New York City. 25214_002_0765.JPG (Photo by Dimitrios Kambouris/WireImage for CNN)
LATE NIGHT WITH SETH MEYERS -- Episode 613 -- Pictured: (l-r) Journalist Chris Cuomo during an interview with host Seth Meyers on November 22, 2017 -- (Photo by: Lloyd Bishop/NBC/NBCU Photo Bank via Getty Images)
NEW YORK, NY - NOVEMBER 01: Chris Cuomo attends the 10th Annual Stand Up For Heroes Show at The Theater at Madison Square Garden on November 1, 2016 in New York City. (Photo by Debra L Rothenberg/FilmMagic)
EAST HAMPTON, NY - JUNE 03: Eric Gunhus, Bebe Neuwirth, Christina Greeven Cuomo, and Chris Cuomo attend the 2017 Dancers for Good Benefit at the Ross School Court Theater on June 3, 2017 in East Hampton, New York. (Photo by Sonia Moskowitz/Getty Images)
NEW YORK, NY - NOVEMBER 05: (L-R) Bob Woodruff, Amanda Martino, Senior Airman, Air National Guard, Active and CNN anchor Chris Cuomo attend The New York Comedy Festival and The Bob Woodruff Foundation present the 8th Annual Stand Up For Heroes Event at The Theater at Madison Square Garden on November 5, 2014 in New York City. (Photo by Monica Schipper/Getty Images for New York Comedy Festival)
UNITED STATES - MARCH 02: Chris Cuomo arrives for premiere of the movie 'The Man in the Iron Mask' at the Ziegfeld Theater. (Photo by Richard Corkery/NY Daily News Archive via Getty Images)
NEW YORK, NY - MAY 28: (L-R) Noah Galloway, Jamie Boyd and Chris Cuomo attend the 2015 HELP USA's Hero Awards Dinner at Cipriani 42nd Street on May 28, 2015 in New York City. (Photo by Steve Mack/FilmMagic)
Julie Chen, Matt Blank, CEO of Showtime and Chris Cuomo (Photo by Stephen Lovekin/WireImage)
John Quinones, Cynthia McFadden and Chris Cuomo from Primetime Live (Photo by Jim Spellman/WireImage)
Jeff Sachs, Chris Cuomo and Greg Bello at the Screening of the movie 'Love & Sex' hosted by Famke Jannsen at Ted Fields House at Goose Creek in the Hamptons. (Photo By: Richard Corkery/NY Daily News via Getty Images)
PARADISE ISLAND, BAHAMAS - NOVEMBER 04: (L-R) Chris Cuomo, Cristina Cuomo and Chef Jose Andres attend the weekend opening of The NEW ultra-luxury Cove Resort at Atlantis Paradise Island on November 4, 2017 in The Bahamas. (Photo by Mike Coppola/Getty Images for The Cove, Paradise Island)
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On Tuesday morning, his co-host Michaela Pereira nagged him, saying: "I asked you yesterday how your weekend was and you didn't say a word."
Cuomo replied: "In truth, I was leaving it alone because I didn't want to reveal the guy. I didn't want to embarrass him ... We're talking about it because someone called it in and put it in the news, and it wasn't me."