They got into trouble around 2:30 p.m. near the north jetty at the Fort Pierce Inlet.
Officer Keith Holmes jumped into the water with a life preserver and brought the girls to a St. Lucie County Sheriff's Office boat, according to Fort Pierce police.
Police say the group was using kick boards and the current pulled them from the shore and they couldn't get back to land.
James McArthur said he heard screaming, and called 911.
"...It was about five or six people. Like I said, I noticed them over there, and then I noticed the surfboard in the water, going down the inlet. And out there in the water. And that's when, you know, I - they were yelling, and then I got on my phone and I called," he said.
"Whenever entering one of our local waterways, swimmers should be cautious and aware of water conditions and dangerous surf conditions. We are extremely fortunate; if not for the quick actions of Officer Holmes, the Saint Lucie County Sheriff Deputies and the United States Coast Guard this incident may have had a tragic ending," Deputy Chief Frank Amandro said in a release.
Saint Lucie County Fire Rescue treated four of the teens for cuts and scratches. One was transported with non-life threatening injuries.
St. Lucie Medical Center no longer on lockdown
A concern over a gun caused a lockdown at St. Lucie Medical Center, according to Port St. Lucie police.
Flagler Memorial Bridge to reopen Saturday
The Flagler Memorial Bridge in West Palm Beach is reopening on Saturday after being closed for six months.
Murder conviction overturned causing retrial
A Palm Beach County man who received a life sentence for first-degree murder in 2010 had his conviction set aside by an appeals court.
Man shot near West Palm apartment complex
A man was shot overnight near the Ponte Verde apartments, according West Palm Beach police.