More than a dozen divers and rescue workers from three agencies spent all day Tuesday searching without success for the body of a Lawrenceville man presumed drowned in Lake Lanier.

The search could continue through at least Thursday.

Forsyth County Fire Department Capt. Jason Shivers said the search area exceeds a square mile near Six Mile Creek, directly east of Shady Grove Campground.

Rohan Mathew, 27, is believed to have drowned Sunday afternoon after sliding off a water slide on a rented houseboat. The houseboat drifted away from him in high winds and Mathew yelled out for help before going under, authorities said. A witness jumped into the water to rescue Mathew but couldn’t find him.

The area where Mathew was last seen is about 80 feet deep and heavily wooded underwater, officials said.

But after Monday’s severe storms, his body may have been moved some distance by the natural flow of water, Shivers said.

“We’re searching a very large area,” Shivers said.

Depths of the water are 80 to 100 feet, and divers are contending with thick woods under the surface.

“It’s very dangerous,” Shivers said. “These conditions have been described to me as prime conditions to lose a diver. We’re going to do everything we can to bring this family closure, but working within the limits of acceptable risk.”

The initial search for the body was called off Sunday afternoon and delayed until Tuesday because of weather conditions.

Shivers said divers will return today and Thursday if necessary.

Seven divers from the Forsyth County Fire Department, four divers from the Hall County Sheriff’s Office and several officers from the state Department of Natural Resources are working on the search, using three sonar devices for underwater imaging.

“We are getting very clear pictures of the bottom of the lake,” Shivers said. “But in the areas that are wooded, the conditions are very difficult.”