Authorities say a 4-year-old Portland boy is expected to recover after he nearly drowned at Sabbathday Lake in New Gloucester on Monday afternoon.

The boy and his mother were on a family outing when he jumped off a dock at Bald Hill Beach and failed to resurface, Capt. Scott Stewart of the Cumberland County Sheriff’s Office said.

The boy was wearing “arm floaties,” or inflatable armbands, when he went into the water, investigators said. It wasn’t clear if the flotation aids came off or why they failed to keep him on the surface.

Bystanders pulled the boy from the lake, which was about 4 feet deep at that point, and notified emergency responders around 3 p.m.

“They told responders that the child was pulseless,” Stewart said. Someone, he is not sure whether it was bystanders or members of the New Gloucester Fire and Rescue Department, revived the boy by administering CPR.

“He seemed stable and alert,” Stewart said, adding that a Lifeflight helicopter was called to assist, but was not needed.

The boy, whose name is not being released, was transported by ambulance to Maine Medical Center in Portland, Stewart said.

“He is going to recover,” Stewart said.

Dennis Hoey can be contacted at 791-6365 or at:

dhoey@pressherald.com