That's the warning issued Sunday by forecasters, who cited rough waves and potential rip currents being spawned by Hurricane Igor.
Swimming has not been banned at any New Jersey beaches, but yellow flags have been posted at many sites to warn swimmers about the conditions.
The National Weather Service says swells kicked up by the storm will likely be in the 5- to 8-foot range Sunday. The swells are expected to build as the day progresses, and will likely continue through Monday.
Officials warn that swimmers should only be in areas where lifeguards are stationed and should not swim alone - even if waters don't appear to be risky.
Rip current awareness from the NOAA.