Forsyth and Hall County authorities spent Sunday searching for a Lawrenceville man who went missing in the choppy, frigid waters of Lake Lanier earlier in the day.

The man, whose name is being withheld pending notification of next to kin, went down a slide on a houseboat without a life jacket and into the water about a half-mile from shore in Forsyth County, said Sheriff Ted Paxton.

Authorities gave his age as either 26 or 27 and said his family is in India.

“Very quickly, other people on the boat realized he was in distress. There was another (person) on the boat who grabbed a life jacket and jumped in, trying to get to him, but wasn’t able to,” Paxton said.

The Forsyth County Sheriff’s Office was called at about 1:55 p.m.

Authorities, also including the Georgia Department of Natural Resources, launched rescue efforts from Shady Grove Park, which is near Browns Bridge Road, Paxton said.

About 10 people were on the boat, which had traveled from a marina in Hall County. Paxton didn’t have the name of the marina.

Robin Hill, a DNR spokeswoman, said one of the other passengers aboard the boat tried to throw the man a life jacket, “but he couldn’t get to it.”

Paxton said, “It’s very deep water where he is at.”

“One of the things that’s been hampering the (rescue) efforts is the wind. We’re probably experiencing sustained winds of ... 25 to 30 mph.,” he said. “The lake is not conducive to any boat traffic on it. I mean it is really, extremely choppy.”

In addition to diving efforts by Forsyth and Hall, authorities also used a hand-held sonar device in their search efforts.

Paxton also was concerned a forecast of overnight thunderstorms would further hurt search efforts.

He cautioned lake visitors to be careful even as weather conditions improve.

“Yeah, it’s been nice; we’ve had some warm weather. But the water temperature in the lake is just not conducive to people being in the lake right now,” Paxton said.

At a temperature of 65 degrees, “being in the water ... is going to bring on the effects of hypothermia rather quickly,” he said.