Safe at Sea: Rip tides versus rip currents
This “winter,” I have received numerous “Rip Current Alerts” from my weather app and I finally investigated not only what exactly a rip current is, but also how it differs from a rip tide. Often they are used interchangeably, but mistakenly. In keeping with the previous columns regarding poor weather conditions and the resulting heavy seas, this one on rip tides and rip currents is fitting.
According to Wikipedia, a rip current — often simply called a “rip” — is a specific kind of water current that can occur near beaches with heavy-breaking waves. A rip is a strong, localized and narrow current of “overflow” water, which moves directly away from the shore, cutting through the lines of breaking waves like a river running out to sea. A rip current is strongest and fastest nearest the surface of the water.
Thus, strong winds and waves, in particular, bring to shore excess water which needs to return to the open water. That “return” occurs in specific areas in the water: in a deeper water channel, a break in the shoreline (think off-shore sand bar, for example) or an intermittent reef. The excess water seeks that path and creates a “rip.” Perhaps a better title might be a “backwash.”
There is a common misperception that a rip current is an “undertow.” A common misbelief is that either a rip current or an undertow can pull a person down and hold that person under the water. A rip simply carries a floating object like a person, swim raft or beach ball out to just beyond the zone of the breaking waves, which is the point at which the strong current lessens and releases its “grip.” It is important to note though that a rip current is frightening and, as a result, a frightened swimmer, especially a child, may well be terrified and that terror may lead to serious injury, even drowning.
A rip tide is a very strong current that occurs as the tide pulls out of an inlet, a lagoon or marina, where water flows steadily out to sea during ebb tide. Another (local) area susceptible to a rip tide is within estuaries.
Just that piece of information alone should tell us that rip currents are more hazardous for swimmers; rip tides are more important for boaters. Rip tides are caused by the gravitational pull of the moon and the sun and occur approximately every 12 hours in Southwest Florida.
Being safe at sea equates to knowing — literally knowing — our waters.
Pat Schmidt is a member of America’s Boating Club of Sanibel-Captiva. For more about the chapter and its courses, visit www.sancapboating.club or contact Commander@SanibelCaptivaSPS.org or 239-985-9472.