Rip currents can occur at any beach with breaking waves, including the North American Great Lakes. They are channeled, powerful water currents flowing away from the shoreline, through the surf zone and out past the line of breaking waves.
Rip currents put weak or non-swimmers at great risk. Some currents travel one to two feet per second. Severe currents can reach eight feet per second, faster than any human can swim.
Jason Goodman, Graduate Student MIT noted in Mad Scientist, “surfers often use them as 'express lanes' to get back into deep water. But don't do this unless you're a strong swimmer, have a surfboard for flotation and know exactly how far out the riptide will take you. "
How Rip Currents Form
Normally, waves bring water ashore, pushing water ahead of them. This water gets picked up by the longshore current that flows parallel to the shore and eventually out to sea.
Sometimes water gets trapped on the shoreline due to changes in the beach or by obstructions. It's not strong enough to break into the longshore current. The accumulated water eventually breaks through a small area in the longshore current, creating a swift-moving channel of water flowing out to sea.
Rip Current Myths
The term riptide is a misnomer - a rip current is not a tide.
A rip current does not pull people under water. It pulls them away from the shore. Most deaths occur when swimmers try to swim against the current and drown from panic, exhaustion or poor swimming skills.
A rip current and an undertow are different, though related. An undertow happens when piled-up water cannot escape back through the waves. Instead, the water flows backwards under the waves.
Where Rip Currents Typically Occur
Rip currents can happen wherever there are obstructions, including:
- Breaks or low spots in sandbars
- Abrupt topography changes on the shore
- Water surrounding piers or jetties
Although rip currents occur on surf beaches almost daily, average sea conditions keep the current speed fairly slow. Sometimes certain tidal, wave and beach conditions will escalate the rip current to very dangerous speeds. Increased wave heights and frequency could indicate a strong rip current.
Signs of a Rip Current
- visible channel of choppy water
- water a different color in a specific area
- distinct breaks in a wave pattern
- visible line of seaweed and foam moving away from the shore
NOAA advises wearing polarized sunglasses to more easily see the signs of a rip current.
Rip Current Safety Tips
- Learn how to swim in surf.
- Wear a flotation device if unsure of the water.
- Be cautious swimming at unguarded beaches. .
- Obey lifeguards' orders and instructions.
- Never swim alone.
- Stay at least 100 feet away from piers and jetties.
What to do if Caught in a Rip Current
Never swim against the rip current - it is much faster than most swimmers.
Swim out across the rip current at an angle parallel to the shoreline. Usually a rip current is less than 100 feet wide.
If unable to swim across the current, tread water or float while being carried out by the current. The rip current usually subsides 50 to 100 yards from shore.
Once out of the rip current, swim to shore at an angle.
If unable to swim to shore, wave your arms and shout in order to attract attention.
According to the National Ocean Atmospheric Administration (NOAA), “Over 100 drownings due to rip currents occur every year in the United States. More than 80% of water rescues on surf beaches are due to rip currents.”
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