Rip Currents in the Great Lakes

Every large body of water has a current running along its shoreline caused by the angle of the waves coming into shore. In the Great Lakes this current typically, but not always, runs in the same direction and is commonly referred to as the long-shore current. While this current is rarely if ever strong enough to cause a problem for swimmers, its effects can be deadly.

Without the long-shore current, the land would continue to slope smoothly downward (see fig. 1). However, the long-shore current erodes a low area just off shore, creating a trough and a sandbar (see fig. 2). As the waves wash in, the sandbar holds them in. This in turn creates an area where the water is slightly higher just off the shoreline.

Eventually, the amount of water becomes too much for the sand bar to hold. When this happens, the sand bar will break and the water it was holding with rush very quickly through the new opening. This is called a rip current or rip tide, and it is extremely dangerous.

When one is caught in a rip current, the swimmer will be pulled hundreds of yards away from shore and into deep water very quickly. The current is usually too strong for even the strongest of swimmers to fight. In areas where beaches are a major tourist attraction, several people die every year because they were caught in a rip current and lacked the education to survive it.

So how can you protect yourself? First and most obviously, don't swim when conditions for a rip current are good. There are two factors that, together, create a high rip current danger. The first is large waves. When there is more water being pushed into shore by the waves, there is more water to build up and create a rip current.

The second thing to look for is a large, dramatic sand bar just offshore. You can usually spot the sand bar by finding where the waves break before they get to shore. If the sand bar is very large, if the water in the trough is over your head but on the sand bar only goes up to your waste, conditions are ripe for a rip current.

If you do find yourself caught in the current, there are several things you can do to stay alive. First and more important, don't try to swim against the current. You will simply waste your energy. Allow the current to carry you out and swim sideways, parallel to shore, to get yourself out of it. After the current stops pulling you off shore, then swim in using an easy, maintainable stroke.