* WHAT...Dangerous rip currents. * WHERE...Eastern Essex MA, Southeast Middlesex MA, Suffolk MA, Eastern Plymouth MA, Barnstable MA, Dukes MA and Nantucket MA Counties. * WHEN...Through this evening. * IMPACTS...Rip currents can sweep even the best swimmers away from shore into deeper water. Swim near a lifeguard. If caught in a rip current, relax and float. Don't swim against the current. If able, swim in a direction following the shoreline. If unable to escape, face the shore and call or wave for help.