CHICAGO (CBS) — Swimmers were being advised of dangerous conditions on Lake Michigan on Tuesday, due to high waves and strong currents.

The National Weather Service has issued a beach hazard statement from 9 a.m. Tuesday through late Tuesday night, and the Chicago Park District has issued a swim advisory for all beaches on Lake Michigan due to “rough surf.”

The National Weather Service said waves of 4 to 6 feet were expected all along the lakefront Tuesday, with some waves reaching as high as 8 feet on occasion. Strong rip currents and structural currents also were expected.

“Rip currents are powerful channels of water flowing quickly away from shore, which occur most often at low spots or breaks in sandbars,” the National Weather Service said in a beach hazards statement. “Structural currents form along piers where longshore currents and wave action flow into the structure. Rip currents and structural currents can sweep you into deeper water.”

Although swimmers are allowed to go in the lake when a swim advisory has been issued, they are advised to use caution, and must follow lifeguards’ instructions at all times.

Rip currents don’t pull swimmers under the water, but rather away from shore. Swimmers drown when the panic and try to swim toward shore against the current and become exhausted.

If you get caught in a rip current, stay calm and swim parallel to the shore until you are out of the current and then you can swim toward shore. Rip currents are typically narrow and once you swim to the side, you can escape.

To monitor conditions at all Chicago beaches, click here.