Lifeguards and state parks officials are warning beachgoers about the risk of rip currents.

Lifeguards at Jones Beach say they had 30 rescues Sunday, and all were related to rip currents.

They say the best way to stay safe is to swim near a lifeguard.

State parks officials say they have over 250 lifeguards monitoring the water at Jones Beach.

They say they use a flag system to keep swimmers safe. Anyone getting in the water should swim in between the green flags that are in front of an open lifeguard stand.

Red flags mean danger or that an area is unguarded, and people should avoid swimming there.

Lifeguards say wave do not have to be large for a dangerous and potentially deadly rip current to form. They say a rip current is a narrow channel of fast-moving water that pulls people out to see, not under the sea.

"One of the biggest misconceptions is that a rip current will pull you down and underwater and that's not the case," says lifeguard supervisor Cary Epstein. "It's people that start to panic and get nervous and use their energy, that's what ultimately causes them to sink."

Officials say anyone feeling themselves getting pulled further away from the beach should swim parallel toward the beach until the ocean does not feel like it's pulling them.