The victims have been identified as 51-year-old Brian Warter and his 48-year-old girlfriend, Erica Wishard, both of Downingtown.
The family was swimming around 1:30 p.m. behind the Marriott Hotel when the couple and two of their children were swept out by a rip current.
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Police said the kids were able to break the current and tried to help their parents, but the water was too dangerous and they were forced to swim back to shore.
"Multiple witnesses told our investigators that both the male and female, who are now deceased, got in the ocean, right into a rip current and immediately were pulled from the shore. One of the children of the deceased tried to yell to them instructions on how to swim parallel to the shore, but they were in panic mode and unfortunately went under," Martin County Sheriff's Office Chief Deputy John Budensiek told WPBF 25 News.
"Lifeguards entered the water and were able to pull out one unconscious person and begin CPR, " said MCFR officials.
A few moments later, another unconscious swimmer was rescued, and CPR was initiated.
Those life-saving efforts continued in the ambulance and at the hospital, but doctors said they were not able to be saved.
Both victims were taken to Cleveland Clinic Martin North Hospital, where they were pronounced dead.
Neighbors of 51-year-old Brian Warter are taking the loss of life hard.
"He was a wonderful neighbor. We helped him out with his dogs. He helped us out with our dogs, with gardening advice, and taking care of the yard. Very nice guy. Very nice neighbor," said Lauren Aldridge.
Rip currents are very dangerous along the East Coast, including at the Jersey shore.
Local reports indicate the couple were swimming during a High Hazard Warning Flag advisory, which means high surf and strong currents.
"It is a beautiful place, but they don't realize how dangerous it can be the ocean is strong and final when it gets a hold of you," said Martin County Sheriff Deputy John Budensiek.
Warter had two older boys in their late teens. Wishard had four children.
Neighbors say they knew little of Wishard but had seen her more at the home in recent months, and the two seemed to have a genuine relationship.
"It seems like a great relationship," said Aldridge. "So, we are at a loss for words about the whole thing."
Experts warn that if you get caught in a rip current, do not fight it, and instead let it take you out to sea.
You should also swim horizontally to the coast to get out of one.
A Martin County Sheriff's Crisis Intervention Team Deputy is helping the couple's children as they await the arrival of other family members.
RELATED: How to survive a rip current
VIDEO: Survive a Rip Current