EASTERN SUSSEX –– When many people take a dip into the ocean, their biggest fear is getting bitten by a shark or stung by a jelly fish. But the real threat is the water itself, not the creatures residing in it.

According to Kris Knutsen, aquatic safety administrator and the beach patrol captain for Delaware State Parks, rip currents pose the biggest threat to swimmers, especially the novice and weak.

“Rip currents account for 80 to 95 percent of beach patrol rescues,” Mr. Knutsen said. “A rip current can very quickly take a bather from knee- or waist-deep water, to water over their head.”

A rip current, also known as a rip tide, is a strong but narrow current moving directly away from shore, that travels directly through waves.

“Rips currents typically run perpendicular to the beach, but may be skewed to the north or south, depending on the incoming swell,” Mr. Knutsen said.

“Rips can be identified by their sandy-brown coloration, mushroom shape, and decreased wave size within the neck of the rip.”

Although rip currents may be spotted by the eye, in many cases they catch swimmers by surprise –– or even if the lull in waves is identified, beach goers may have it mistaken for gentler waves instead of a dangerous current, making weak swimmers unknowingly enter hazardous conditions.

“Persons caught in a rip may start to panic, and make poor decisions about how to get out of the rip,” Mr. Knutsen said. “Even relatively strong swimmers are unable to swim against a typical rip current, and most who try will tire quickly without making any progress.”

Lifeguards hold the key

The best preventative measure in avoiding drowning due to a rip current is to swim on a beach patrolled by lifeguards. The Delaware State Parks system currently has about 50 lifeguards patrolling four different coastal swimming areas from Lewes to Fenwick Island.

Swimmers in guarded areas have only a 1 in 18 million chance of drowning according to the U.S. Lifesaving Association. There were only 14 drownings on unguarded beaches in the entire country in 2015.

But that doesn’t mean swimmers should venture out when they know there is a rip current –– usually about one a day forms at Delaware’s beaches as rip currents are a natural occurrence in the ocean’s wave cycle.

Mr. Knutsen said it isn’t embarrassing to rely on a lifeguard to get out of a rip current. The U.S. Lifesaving Association’s 2015 national report showed that out of the 95,023 rescues, 48,213 were rip current-related.

“This kind of rescue is performed by beach patrol members on a regular basis and is actually fairly routine,” he said. “Most rescued individuals are not injured, nor do they require medical attention.”

Other dangers

Although rip currents should be a major concern for beach goers, there are other times to use caution as well.

Mr. Knutsen said in his 25 years of guarding at the beach, he has seen injuries including dislocated shoulders and spinal damage from people just trying to have fun either surfing or body boarding.

“Injuries are especially likely for those who ride head first, ride straight into shore, or those attempting to ride shore breaks and plunging waves,” he said.

“Those wanting to surf should learn to look for spilling or rolling waves, assume a proper body position, and ride the shoulder of the wave off to the side.”

Another natural concern like rip currents is storms.

“Those who elect to stay on a beach during lightning storms probably take the greatest risk,” Mr. Knutsen said. “Lightning is not absorbed directly into the sand, but rather skitters across the surface. Patrons standing several hundred yards away from a strike may still be affected. Those who elect to seek shelter under an umbrella or tent, and those who continue to hold a fishing pole are only encouraging a direct strike.”

So although the beach and ocean are a fun playground, it’s always necessary to exercise caution, swim near a lifeguard and always follow directions given by the guards.

“Remember, the chances of being caught in a rip, injured in the surf, buried in a sand cave-in, and/or struck by lightning, are astronomically higher than any shark encounter,” Mr. Knutsen said.