Nik Rajkovic / news@whmi.com

The Oakland County Sheriff's Office reports the body of an 84-year-old Sylvan Lake man was recovered Friday night after his unattended boat was found drifting in the lake hours earlier.

The body of Louis William Petro was discovered about 10 p.m. by divers from the Oakland County Sheriff’s Search and Rescue Team and Southeast Michigan Dive Group in five feet of water approximately 200 feet from the shore. The preliminary cause of death is drowning. He was not wearing a life jacket.

“In an already extremely tragic summer, the loss of another person while they were enjoying the water is very sad,” Sheriff Michael Bouchard said. “While we don’t know what happened in this case yet, we encourage people if they are not strong swimmers, or they are alone in the water to consider using a floatation device.”

It was the 11th drowning in an Oakland County lake so far this year.

Petro was seen taking his 18-foot Glastron pleasure boat out onto the lake by other boaters at approximately 2:30 p.m. Friday. He is a regular boater on the lake and was alone in the boat. At about 5:15 p.m., Petro’s unoccupied boat was seen drifting in the water and authorities were notified.

Other boaters on the lake tied up the drifting boat to prevent it from getting in the way of other boaters.

Deputies found Petro’s personal effects, including his cell phone, wallet and car keys in his boat. No signs of a struggle or foul play were discovered. No evidence of any alcohol or drug use was found.