MADISON, Wis. -- Several drownings at Lake Michigan beaches in recent years underscore the importance of understanding Great Lakes currents and how to escape from them, according to Jim Lubner, water safety specialist at the University of Wisconsin Sea Grant Institute.
The two most important currents to know about are longshore and rip currents, Lubner said. Longshore currents flow along the shoreline, and rip currents flow roughly perpendicular to the shoreline on the surface of the water.
"You always want to swim perpendicular to the currents," Lubner said. "In the case of longshore currents, that's perfectly natural. The current will carry you along, parallel to the shore, and you should just swim toward shore."
Rip currents are trickier, Lubner said.
"With rip currents, you get pulled out away from shore, and your natural instinct may be to swim directly towards shore, against the current. But it's best to swim at right angles to the current, which in this case means swimming parallel to shore. That way, you get out of the current the fastest. Once you are out of the current, you can swim to shore much easier," he said.
"These currents are usually pretty narrow, so you can get out of them in a short distance," Lubner said.
Some signs of rip currents are patches or lines of foam, debris and discolored water moving away from shore. Another sign is a stretch of breaking waves whose heights are lower than the waves to either side.
"Remember that the dangers of currents multiply when the water is cold," Lubner said. "Cold water drains heat from the body very quickly and interferes with muscle operation and coordination. You can't swim very far or fast in cold water."
Created in 1966, Sea Grant is a national network of 30 university-based programs of research, outreach and education dedicated to the protection and sustainable use of the United States' coastal, ocean and Great Lakes resources. The National Sea Grant Network is a partnership of participating coastal states, private industry and the National Sea Grant College Program, National Oceanic & Atmospheric Administration, U.S. Department of Commerce.
For More Information: Jim Lubner, water safety specialist, 414-227-3291 John Karl, science writer, 608-263-8621