It happened around 3 p.m. at the Vista Point boat ramp on North Pea Ridge Road/SR 1700 in Pittsboro.
Authorities told ABC11 that Ricky Hill was tubing with his two grandchildren when at one point they fell off the tube. He and his daughter, who was on a boat, tried to help the kids get back on, but Hill ended up going underwater.
They said Hill was not wearing a life jacket, but his two grandchildren were. His daughter was unable to help him.
Search crews are currently in recovery mode. Crews are using sonar devices, dive teams and dogs to try and find Hill, while his grief stricken family waits for word.
Family described the 50-year-old as a hard working man, who often came to the lake to go fishing, and who lived for his family.
"It's hard because you know he's out there and we want to go out there and get on the water but you the safety for the crews, the divers, the best thing for us to do is stay away and give them the chance to do their job," said Hill's brother-in-law Bill Lunsford.
New equipment was brought in Tuesday to find Hill. It includes a submergible camera that can go down into the water as deep as 300 feet.