Talk:Undertow (water waves)

Removal of speedy deletion tag

I have removed the speedy tag because this article is more than just a definition; it gives the environmental role of the natural phenomenon as well. Cheers! Scapler (talk) 04:01, 4 October 2009 (UTC)

This article needs expansion. It is obvious that a reasonably lengthy article can be written that explains, inter alia:

• conditions creating undertow
• physics of undertow
• ways to identify undertow

plus many other topics. The notion that the topic is only suited for a dictdef (even if that was the state of the article) is an odd one. ^Bongo_matic 07:07, 4 October 2009 (UTC)

Distinction from rip tide

CBS new article ChildofMidnight (talk) 04:52, 4 October 2009 (UTC)

This wikipedia article makes a big thing of saying that riptides/rip currents are different from undertows -- But I don't see where the distinction is (other than that the former are localized). The articles on rip tide and rip current do describe them enough to give the difference: they cut through rather than run under incoming waves..37.99.32.45 (talk) 15:01, 31 August 2020 (UTC)

Nature of hazard

I am concerned that the article not perpetuate two dubious hazards attributed to undertows: that they can pull people under the surface, or that they can pull people out to sea (as a rip current). These effects are not substantiated in the reliable material I have run across (e.g. the cited source What is an undertow and a ripe tide?). This article seems like a notable opportunity for Wikipedia to appreciably contribute to an accurate broad public understanding of a bona fide safety hazard prone to inflammatory mischaracterization, if proper sources can be found to cite. ENeville (talk) 15:35, 28 May 2010 (UTC)

In the meantime I cleaned it up a bit without searching for sources. Invertzoo (talk) 18:13, 5 August 2010 (UTC)

An undertow can certainly pull you under, unless the signs that litter every dam on the continent are using the wrong term to refer to the downwards pulling effect of falling water. Another example is a sinking car. - ʄɭoʏɗiaɲ ^τ _¢ 22:04, 24 February 2012 (UTC)

If you can find a good reference to the word "undertow" used in warning signs at dams and similar places where water is falling hard and fast underwater, then great, please add it! I myself would call that "undersurface turbulence", not undertow. Invertzoo (talk) 17:48, 1 January 2014 (UTC)

Gee, why not just do a google search for "dam undertow" and "river undertow" instead of asking for references. Do you live in a cave?

I don't know about reliable sources, but from personal experience, I know that undertows are frightening and dangerous. Here's an article that might be about a death due to undertow (the text refers to undertow, but the description is not clear): https://globalnews.ca/news/4385315/undertow-dangers-toronto-woodbine-beach/ — Preceding unsigned comment added by 37.99.32.45 (talk) 15:32, 31 August 2020 (UTC)

Substantial re-write

Today I was BOLD and substantially re-wrote this article. All modern sources I could find define "undertow" as a rip current plain and simple, although they often also mention the popular scary idea of being pulled under and held under until you drown. In fact this article should probably be reduced to a redirect page to rip current, aka rip tide.

The folk definition of the "undertow", as something omnipresent in the shallow water near a beach that can pull you under and hold you underwater until you drown, is a complete misapprehension, a negative fantasy rather like the bogeyman. I imagine that this folk belief was probably inspired by hearing about drownings that were due to rip currents, along with a complete lack of knowledge of what a rip really is.

Invertzoo (talk) 17:42, 1 January 2014 (UTC)

Update

I recently got a message on my talk page from an oceanographer who explained what the proper scientific use of the term is. However the explanation was very dense, and so I am most sure I understand it. I also left in the popular misunderstanding, as I feel that is important too. Invertzoo (talk) 23:38, 29 May 2014 (UTC)

Winslow Homer

Undertow or rip current? Upsetting to the politically correct?

Winslow Homer has a painting of two men rescuing two attractive women from the surf in a decidedly Neanderthal manner. Homer called this an "undertow", though it's not clear whether he really meant a rip current. The water's only knee deep, so perhaps it is an undertow. In that case, it's hard to see why the women needed "rescuing" in this fashion. On the other hand, perhaps the woman were dragged in from the deep, in which case it would have been a rip current. There does seem to be the appearance of a rip in the calm water on the right side. I'll let other editors decide if they want to use this image. --Epipelagic (talk) 23:36, 5 July 2014 (UTC)

When in doubt, try...English.

Greetings esteemed editors. Wikipedia articles at their best explain their topics to readers in plain English--which an ordinary literate person can understand. This article is a FAIL. Could some reader who understands undertows please, please explain it to the rest of us in English--with appropriate references, of course? Many thanks to the person who can do it. Tapered (talk) 19:25, 25 July 2015 (UTC)

oceanography? undertows are quite dangerous in rivers, there is no confusion

'undertow' is often used to describe river currents, as in when water flowing over a dam, waterfall, or submerged rocks can create a powerful downward current that can suck objects and people down and trap them in an underwater vortex. In this context, there's very little confusion with rip-currents. River undertows are generally persistent, rather than intermittent or cyclical like coastal currents. As someone thats spent a whole lot of time wading rivers, I can tell you theres at least two kinds of undertow. A dam, waterfall, or steep slide gives the water a signifigant downward momentum, which creates undertow when it enters a 'pool' at the base. Water flowing over underwater obstructions creates an undertow, Ive been sucked down and trapped myself.. I think this is similar to when wind flows over a wall or other obstruction, theres a strong downdraft and vortex on the 'leeward' side... — Preceding unsigned comment added by Fencelizard (talk • contribs) 15:53, 1 December 2015‎

Hello Fencelizard, as stated in the article name -- undertow (water waves) -- the subject is the undertow occurring under water waves, most notably near the coasts of oceans, seas and large lakes. If there is a notable subject of undertow in rivers, it could be created as a new Wikipedia article. -- Crowsnest (talk) 20:50, 1 December 2015 (UTC)

Changes to the lead of the article

The following additions have been added to the start of the article lead:

Undertow in water waves is a current that is physically experienced as the off-shore pull that a person feels when they are standing in the water within the breaking-wave zone near a beach. People feel this current most strongly near their feet, as each breaking wave advances towards them.

Despite the good intentions to attempt to improve the article: as far as I can see, this is original research. It is not backed-up by the scientific research on the topic and in contradiction with physics principles:

• an "off-shore pull" is a force, while the subject is a current -- drag forces are quadratic in the current velocity, so in the highly oscillatory and strongly non-sinusoidal velocities in the surf zone, one does not experience the currents directly. This is also clear since most people are pushed over shorewards when being hit by a breaker;
• the undertow is a mean current in a highly oscillatory velocity field, the oscillations being larger than the mean -- how could one detect with any accuracy this mean velocity from the experienced push and pull (also given the quadratic dependence of the physical felt forces on the flow velocity);
• where is there any objective evidence (reliable references) that "... People feel this current most strongly near their feet, as each breaking wave advances towards them ...";
• as was in the start of the lead's earlier version, the context of undertow is the science of oceanography.

Also, as stated further on in the lead (and in previous versions also further-on in the article) undertow occurs both in breaking waves in the surf zone, as well as in non-breaking waves (outside the surf zone). See, e.g. [1]. -- Crowsnest (talk) 18:54, 3 August 2016 (UTC)

dutch muistroom

https://nl.wikipedia.org/wiki/Muistroom it shows HOW to act while taken, so dont swim AGAINST it but float a bit with the stream, ON surface only of course — Preceding unsigned comment added by 213.17.27.144 (talk) 10:12, 25 August 2016 (UTC)

Dutch "muistroom" is rip current, which is a different topic. -- Crowsnest (talk) 20:16, 25 August 2016 (UTC)

Feels like a math course

I feel this article is a list of math equations. Why is it necessary for people to know the mathematical model that undertows go out in? — Preceding unsigned comment added by 2607:9880:4148:C2:2DDE:4F86:8720:75CB (talk) 12:51, 2 August 2020 (UTC)