Swimmers also need to take precautions this summer and should be aware of locations where potentially dangerous currents can develop. Rip currents are powerful currents that can pull even experienced swimmers away from shore. These currents have been known to develop on some Great Lakes beaches. One such beach is on northern Lake Michigan. The open expanse of coastline along US-2 in Michigan's Upper Peninsula is inviting, but the waters are dangerous under certain conditions, said Michigan Sea Grant Extension Agent Ron Kinnunen, who is a member of the Mackinac County Water Safety Committee Review Team.
Rip currents are generally more prevalent after storms.
However, rip currents can also form where there is a break in a nearshore sandbar or the current is diverted lakeward by a jetty or other barrier. According to the brochure Rip Currents, produced by North Carolina Sea Grant, rip currents can extend 1,000 feet offshore and travel up to 3 miles per hour. The brochure explains that some rip currents may be present for a few hours, while others are permanent. Waves might also be larger and choppier, and foam or other debris might be moving steadily lakeward. If swimmers suddenly find themselves caught in a rip current, it's best not to panic or swim against the current.