Wear a life jacket. The answer to staying safe on Lake Lanier this summer could be that simple, public safety officials said in the wake of a deadly holiday weekend that claimed the lives of four young men.

Jennifer Barnes, a spokeswoman for the Georgia Department of Natural Resources, said a life jacket is the "most important thing if you're going to be on a boat."

"It's the key thing we want to stress," Barnes said. "Make sure you have enough life jackets and make sure you actually put them on."

Two young men from Alpharetta, neither of whom was wearing a life vest, drowned Saturday night after their pontoon boat wrecked on the way back to Port Royale Marina in northeastern Forsyth County.

There were two other drownings in the lake over the Fourth of July weekend, one of which also was in Forsyth. Barnes said "being knowledgeable" is the best way to avoid similar incidents.

"People are going to have to educate themselves," she said. "There's certain things you have to know if you're going to get on a boat."

Barnes added that the DNR offers a free boating safety course on its Web site.

The level of Lanier -- the lowest for a July Fourth in the lake's 51 years -- heightened the danger on the always busy holiday weekend.

In the other two drownings, authorities said the victims waded into steep drop-offs in what they thought was shallow water.

"Many holiday weekends are very active weekends on the lake," Barnes said. "We do anticipate more incidents because there are more people out."

Seven people were cited for boating under the influence on Lanier over the weekend, officials said, and there were five boating incidents.

Authorities recovered the bodies of Lung Mang and Tha Thang early Sunday. Authorities have said the two men drowned trying to free their rented pontoon boat from a submerged obstacle it struck just before a thunderstorm late Saturday night.

Mang and Thang were among nine passengers on the vessel, none of whom were wearing a life jacket, authorities said.

William Archer, rental manager with the marina, said he was upset over the tragedy and saddened that no one on the boat chose to wear a life vest.

"We issue all the safety equipment, but one thing I can't do is force these guys to wear life jackets," he said. "They didn't wear their life jackets and they couldn't swim.

"As much as I wish I could be out there with them and instruct them to put their life jackets on, that's something we can't do."

Archer said he has been taking heat from boat owners, some of whom have complained that people who rent boats are contributing to the drownings. But Archer said it's just the opposite.

"They see a rental and automatically think people don't know what they're doing and it's just not the case," he said.

"Anyone can buy a boat and someone just throws them the keys. But when you rent a boat, you have to go through a procedure to get out on the water."

Archer said there's a lot paperwork with boating instructions.

"We go over the navigational markers and we take them out on the water for a test run," he said. "Our customers actually get more of an education than most boat owners, if you think about it."