Divers could go back in the water Monday in search of a Lawrenceville man presumed drowned last week after sliding off a houseboat into Lake Lanier.

Forsyth County Fire Capt. Jason Shivers said the search for 27-year-old Rohan Mathew would be limited over the weekend to shore and surface sweeps.

“We’re searching a huge area of the lake,” said Shivers, adding that recovery efforts have been expanded to a space of about a half-mile by a half-mile.

Mathew went under water May 2 in the area off Shady Grove Campground, where Six-Mile Creek meets the lake.

Authorities said he slid off a water slide on a rented houseboat, which drifted away from him in high winds.

Mathew yelled out for help before going under. Another person on the houseboat jumped in, but couldn’t find him.

The search was hampered early last week by severe storms.

Shivers said the visibility of fire department divers is limited below depths of 20 to 30 feet.

“It’s a dangerous environment for divers and we’re having to use a lot of precautions,” Shivers said.

“We’re just about to the point where we’ve exhausted our people so we’re going to take a break over the next few days from putting divers in the water.”

Shivers said a cousin of Mathew’s from Maryland came Thursday to observe the search. She has been relaying information to the rest of the family in India.

He said those participating in the search are “doggedly determined” to bring closure to the family.

“These guys just will not quit,” Shivers said. “These divers are determined to work until they can’t work anymore to help this family.”

Shivers said sonar was used in Friday’s search.

Thursday afternoon, authorities re-interviewed witnesses who were on the boat with Mathew to get a better idea of where he entered the water.

The county’s Geographic Information Services department has assisted in the search, as well as fire departments from Dawson and Cherokee counties.

Personnel from the sheriff’s offices in Forsyth and Hall counties and the Department of Natural Resources have also participated, as have cadaver dogs.

“The Forsyth County Fire Department offers their extreme thanks to all of the agencies assisting us,” Shivers said.

He also asked boaters on the lake this weekend to monitor the surface and call 911 to report anything suspicious.