(Myrtle Beach, SC) - Hurricane Erin is strengthening, bringing dangerous rip currents and surf as well as rain and wind to South Carolina. The National Weather Service has issued a high surf advisory for South Carolina beaches. That advisory is in effect until 8 p.m. - warning of large breaking waves up to six-feet in the surf zone. The Service says swimming and surfing conditions will be dangerous- and rip currents can sweep those on the water away from shore.