UPDATE (Thursday 7:15 p.m.) - As the search for a drowning victim continues, the Tennessee Wildlife Resources Agency is releasing the victim's name.
Hector Guillermo Mercado Perez, from Norton, Virginia, jumped off a pontoon boat Wednesday and didn't resurface, according to TWRA.
The search resumed just before 9 a.m. Thursday. Rescue team shifted its search to an area about 100 yards away from where authorities were looking yesterday. TWRA said it would use sonar equipment for the search.
ORIGINAL STORY: Rescue crews are at Douglas Lake searching for a 24-year-old man from Virginia who went under and didn't come back up, according to Tennessee Wildlife Resources Agency.
Dispatch said the call came in at 3:29 p.m. for a possible drowning near Mallard Way.
"He left a pontoon boat in this general vicinity, went for a swim, and got about 30 or 40 feet away from the boat and began to struggle," said Matt Cameron with TWRA.
Cameron said another person on the boat tried to help the victim, but struggled himself and was unable to get them both back to the boat.
"At that point the victim went under thee water and was never seen again," said Cameron. He commends the friend for his attempt to save the victim.
According to TWRA, crews are now searching for his body.
The Jefferson County and Sevier County Rescue squads are assisting TWRA. Cocke and Grainger County crews are on the way. The U.S. Coast Guard was assisting but they had to leave, according to TWRA.
Matt Cameron with TWRA said there are 12 boats assisting with search efforts including four from TWRA, two from Newport Rescue, two from Sevier County rescue, two from Grainger County rescue, and two from Jefferson County rescue.
Rescue crews ended their initial search at dark on Wednesday.
When they start again Thursday morning, they ask boaters to stay clear of their search efforts.
"Our move over law went into effect a couple days ago, so if you see a police boat with blue lights on, state law requires you to go around it within 100 feet at a no wake speed," said Cameron.
Cameron said officers do not believe alcohol was involved.
The victim was not wearing a life jacket, something Cameron said could have prevented this tragedy.
"We preach a lot, wear a life jacket any time you're in or around water," he said. "That's the only thing that's going to guarantee that you're going to float."
TWRA and rescue squads extend their condolences to the victim's family.