Friends say Cameron Draughon went under the water around 4:30 p.m. while swimming in the rain-swollen Rockfish Creek in Cumberland County.
Authorities said three teens were horsing around when Draughon dove underwater and didn't come up.
Friends and acquaintances say Draughon, a Gray's Creek High School student, was a good swimmer, which is what makes his drowning so heartbreaking.
"I think what happened is he jumped in and hit his head cause I have hit my head down there before, diving off the cliffs," said resident Derek Gibson. "I believe he hit his head, and came up and was real dizzy and the undertow pulled him under."
Draughon is the second young life lost to a drowning in Cumberland County this month.
On June 6, Cape Fear High School senior Dustin Turner drowned while swimming with friends in the Cape Fear River.
The sheriff's department sent out an alert Thursday warning swimmers to think twice about where to swim.
"When you are swimming in a river or a lake, you are dealing with all different kinds of conditions, especially after a rain," said spokesperson Debbie Tanna. "So we encourage people if you want to swim since we're having weather situations, it's probably best to swim in a pool or somewhere you can see the body of water that you are in."
The sheriff's department says there are no plans to block entrances or close swimming areas along rockfish creek. They just hope summer swimmers young and old will heed their warning.