By Suzanne Monaghan

WILDWOOD, N.J. (CBS) — A rip current was responsible for Saturday’s near drowning of four people in the ocean off the Spicer Avenue beach in Wildwood, New Jersey, according to officials. And they were warning swimmers about a moderate risk of rip currents again Sunday in that shore town.

Rip currents can be found on any beach with breaking waves, but they are difficult for the average person to spot.

“The water is deceiving,” said Wildwood Beach Patrol Steve Stocks. “It’s relatively calm, there’s not a lot of wind, there’s not huge surf.”

Stocks says rip currents typically form at low spots or breaks in sandbars, and are unpredictable in size and speed.

“A rip current may be 25 yards wide, 50 yards wide, 75 yards wide,” he says. “And it will run out maybe 50 yards, maybe 100 yards.”

Stocks says swimming when lifeguards are on duty is the best way to stay safe.

“The lifeguards are trained to identify (rip currents),” he says, “and I would even say that it takes a lifeguard a good few summers before they become really skilled in being able to identify the currents.”

Stocks says eighty percent of rescues nationwide involve rip currents. If you do get caught in one, stay calm. Let the current carry you out, and then swim parallel to the beach until you are out of the current. Then you can make your way back to shore.