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.
See more Cuomo:
CNN anchor Chris Cuomo saves man from drowning in riptide: 'I didn't think, I just went in'
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)
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)
Chris Cuomo of CNN, left, poses with Richard Quest at the CNN Worldwide All-Star Party, on Friday, Jan. 10, 2014, in Pasadena, Calif. (Photo by Chris Pizzello/Invision/AP)
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)
Television journalist Chris Cuomo arrives at the Stand Up for Heroes event at Madison Square Garden, Wednesday, Nov. 6, 2013, in New York. (John Minchillo/Invision/AP)
FILE - This April 16, 2012 file photo shows ABC News' Chris Cuomo at the premiere of the film "Safe" in New York. Cuomo is leaving the network for CNN, where he is expected to host a new morning show. The news came Tuesday, Jan. 29, 2013, from his brother, New York Gov. Andrew Cuomo, as he spoke on a radio show. (AP Photo/Evan Agostini, file)
Julie Chen, Matt Blank, CEO of Showtime and Chris Cuomo (Photo by Stephen Lovekin/WireImage)
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)
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)
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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."