What Is a Rip Current? — In Plain Words

General information only.

The short answer

Rip currents are powerful, channeled currents of water flowing away from shore. That is how NOAA's JetStream page defines them.

They typically extend from the shoreline, through the surf zone, and past the line of breaking waves.

Rip currents can occur at any beach with breaking waves, including the Great Lakes.

How a rip current forms

Incoming waves push water toward the shoreline. This creates an imbalance of water piling up in the surf zone.

To stay in balance, the water seeks the path of least resistance back through the surf. That path is typically a break in the sandbar.

This is where the rip current is the strongest.

Once the flowing water passes through the narrow gap, it begins to spread out. That considerably weakens the velocity and strength of the rip current.

Where they form

Rip currents most commonly form at low spots or breaks in sandbars.

They also form near structures such as groins, jetties, and piers.

How wide and how fast

Rip currents can be very narrow or be hundreds of yards wide.

Rip current speeds are typically 1-2 feet per second. Speeds as high as 8 feet per second have been measured.

JetStream puts it this way: that is faster than an Olympic swimmer.

The seaward pull also varies. Sometimes the rip current ends just beyond the line of breaking waves. Other times, rip currents continue to push hundreds of yards offshore.

Why it is dangerous

JetStream says rip currents are particularly dangerous for weak or non-swimmers. A strong rip current is a hazard for even experienced swimmers.

In NOAA's words: drowning deaths occur when people, pulled away from the shoreline, are unable to keep themselves afloat and swim to shore. This may be due to any combination of fear, panic, exhaustion, or lack of swimming skills.

JetStream adds: once people become tired, they can easily go under without flotation to hold onto.

The numbers NOAA prints

JetStream prints these estimates from the United States Lifesaving Association:

• The annual number of deaths due to rip currents on our nation's beaches exceeds 100.
• Rip currents account for over 80% of rescues performed by surf beach lifeguards.

Those are the Association's estimates, as NOAA prints them on the JetStream page.

Two myths, busted

It is not an “undertow.” Rip currents are sometimes incorrectly called an “undertow.” However, a rip current is a horizontal motion, like a treadmill that carries people away from the shoreline. It is not something that pulls you under.

It is not a “rip tide.” Another incorrect term used is “rip tide.” While rip current strength can be affected by the tide — intensity is enhanced during the hours around low tide — rip currents are not tides and can exist during any part of the tidal cycle.

How to spot a rip current

JetStream says signs that a rip current is present can be very subtle and difficult to identify, especially when the ocean is very rough. At times they can be spotted, especially from higher vantage points than the water's edge.

Some clues include:

• A narrow gap of darker, seemingly calmer water flanked by areas of breaking waves and whitewater.
• A channel of churning, choppy water that is distinct from surrounding water.
• A difference in water color, such as an area of muddy-appearing water, which occurs from sediment and sand being carried away from the beach.
• A consistent area of foam or seaweed being carried through the surf.

JetStream also says you may be able to observe the water flowing away from the beach with the stronger rip currents.

If you are ever in doubt, ask a lifeguard at a guarded beach and they will let you know if they have observed any rip currents.

Before you go in the water

The National Weather Service safety page says: check water conditions before going in by looking at the local beach forecast before you leave for the beach and talking to the lifeguard at the beach.

The same page says: only swim at a beach with lifeguards.

It also says: don't assume. Great weather for the beach does not always mean it's safe to swim or even play in the shallows. Rip currents often form on calm, sunny days.

If you are caught in a rip current — the National Weather Service steps

Attribution: The steps in this section are the National Weather Service's own steps, from its safety page headed “How to Survive a Rip Current.” They are printed here in that page's wording and framing.

• Relax. Rip currents don't pull you under.
• A rip current is a natural treadmill that travels an average speed of 1-2 feet per second, but has been measured as fast as 8 feet per second — faster than an Olympic swimmer. Trying to swim against a rip current will only use up your energy; energy you need to survive and escape the rip current.
• Do NOT try to swim directly into to shore. Swim along the shoreline until you escape the current's pull. When free from the pull of the current, swim at an angle away from the current toward shore.
• If you feel you can't reach shore, relax, face the shore, and call or wave for help. Remember: If in doubt, don't go out!
• If at all possible, only swim at beaches with lifeguards.
• If you choose to swim on beaches without a lifeguard, never swim alone. Take a friend and have that person take a cell phone so that person can call 911 for help.

General information only.