Ocean City, Maryland, safety officials are sending a warning about rip currents and offering a helpful slogan to help swimmers survive one as the unofficial start of summer begins this holiday weekend.

“Rip currents are a leading cause of weather-related death in the U.S. every year,” Ocean City Beach Patrol Capt. Butch Arbin said. “That’s pretty amazing because many states couldn’t have rip currents because they’re not near an ocean.”

He said the Beach Patrol makes between 2,000 and 4,000 rescues every summer. Rip currents, which are fast-moving, powerful channels of water, account for a large portion of those rescues.

Arbin said many swimmers aren’t prepared when they come in contact with a rip current.

“The problem is people go to the ocean and they think of it like a backyard pool,” he told WTOP. “And rip currents are like rivers. In fact, a fast-flowing rip current can move faster than an Olympic swimmer can swim.”

Arbin said rip currents causes many swimmers to panic, unable to get back to the shore.

“The current pulls you away from the beach,” he said. “From the beach, it looks like you’re going down. Truth is, the water is just getting deeper, and you don’t have the energy to keep your head above water.”

The panic that follows sometimes causes family members and friends to attempt a rescue. Arbin said swimmers shouldn’t get into the water until lifeguards are on duty.

“If you see someone in a rip current, don’t try to go help them,” he said. “Very often, when someone goes in to help, now we have two bodies to find, not just one.”

But Arbin said rookie and advanced swimmers could get themselves out of rip currents by remember a simple slogan:

R: Relax
I: I need help
P: Swim parallel to shore

“If a person doesn’t panic and simply swims across it, then they can make their way back to the beach,” Arbin said. “Swim across it like your backyard pool.”