In the wake of what was described as a near-drowning Monday at Lake Mohegan, police warn that to avoid tragedy people need to restrict swimming to areas of the lake posted as safe for swimming.

And in another traditional water-safety trouble spot, Fairfield fire and police personnel scrambled Tuesday afternoon to rescue three people stranded on Penfield Reef by the rising tide. The trio was carried safely back to shore by firefighters' inflatable boat.

In the Lake Mohegan incident, a 23-year-old Bridgeport woman was reported in distress about 2 p.m. at the north end of Lake Mohegan near the Cascades, police said, across the lake from the designated beach area. The woman was apparently briefly submerged under water after inadvertently stepping off an underwater ledge, but was pulled out and revived by relatives, police said.

The woman later told police that she could not remember being pulled to safety. She was evaluated at the scene by AMR Ambulance personnel, but refused further medical treatment.

Police later reiterated earlier warnings that the Cascades area of Lake Mohegan is not considered safe for swimming, and visitors should follow posted directions and swim only in the beach area that is supervised by lifeguards.

A 39-year-old man drowned in the lake last summer, while an elderly woman drowned in July while swimming at Jennings Beach.

On Tuesday about 1:15 p.m., town emergency services received a report of teens stranded on the rocks of Penfield Reef as the tide was rising.

Police, fire and AMR crews were all deployed for the rescue.

Because of shallow water, Police Boat 1 was unable to get close enough to the reef to take the three 18-year-olds aboard, but the Fire Department's Marine 7 maneuvered in closer to the rocks and safely removed them from the reef.

Fire Lieut. Roger Caisse, who piloted the vessel, said in a statement issued later that the teens had "walked out to the reef to take a swim at the lighthouse, but decided it was too much for them, and when they turned to return realized they'd been cut off from the jetty due to the rising tide."

The teens suffered no injuries during the incident, according to an AMR medical evaluation, and they were released when the vessel returned to shore.

"The Fire Department would like to remind everyone to use caution and observe all posted warnings when swimming or boating in unfamiliar waters," Assistant Fire Chief Scott Bisson, the incident commander, said in a statement. "Tides, storms and weather constantly change the height of the sand bars and reefs around Long Island Sound, and may make an area that was previously safe different than expected."