Lyme — A 16-year-old male who went missing Saturday while swimming with friends at Uncas Pond in Nehantic State Forest has died, according to the state Department of Energy and Environmental Protection's Environmental Conservation Police.

The teen was recovered 50 to 60 feet off shore in 20 feet of water, Capt. Keith Williams of DEEP EnCon police said during a news conference Saturday evening at the pond. Lyme Ambulance transported him to Shoreline Clinic in Westbrook while administering CPR about 7:23 p.m.

He later was pronounced dead, DEEP EnCon spokesman Will Healey announced in a 9:01 p.m. news release. His name and town have not been released.

The teen was not a strong swimmer and not wearing a flotation device, Williams said. When the teen disappeared, his friends tried to look for him, then called 911 at 4:38 p.m.

The Connecticut State Police dive team, Lyme Fire Department and Lyme EMS were first at the scene and arrived within 10 minutes of the call, Williams said. State police from Troop F and dive teams from Portland, Middletown and Norwich also responded, Healey said.

The water was 62 to 63 degrees Fahrenheit, Williams said. He emphasized how dangerous it is for people who are not strong swimmers to go into cold water without a life vest.

He cited studies done in water from 45 to 50 degrees showing swimmers can lose speech functions within a minute, muscle functions within 10 minutes and consciousness in an hour.

"The shock hits you very quickly," he said. "If you're not a strong swimmer and you're not wearing a (personal flotation device), it's not a good thing."

This was the third such incident in the state this year, including the death of a child in April after a canoe capsized in North Stonington.

Williams said the hardest part of the job for any police officer, paramedic and firefighter is responding to situations like this.

"We have this problem every year, and it's sad," he said.

e.regan@theday.com