A vocabulary of landscape — a landscape of words
1068 entries
undertow
Undertow is the seaward return flow of water along the bottom of a beach after waves have pushed water up the slope. It is real, it is broad and diffuse, and it will not pull a person out to sea; it acts on the legs, not the body, and it stops in deeper water. What actually carries swimmers offshore is a rip current, which is a narrow fast channel of water returning through a gap in the breakers.
Etymology
The word is a plain English compound from the age of sail, using tow in the sense of pulling. Its persistence is the interesting part: Undertow has become the general word for anything that pulls a swimmer out, so beach signs and news reports use it for rips, and the confusion has consequences, because the two require opposite responses.
Notes
The response to a rip is to stop fighting it, since it is a narrow band and swimming across it at right angles takes only a short distance to clear, while swimming straight against it exhausts a person in water they cannot beat. Rips are visible from a height as a gap in the line of breaking waves, often with a discolored plume of sediment running out through it.