Changes

[[File:lighterstill.jpg]][[File:Undertow-by-Steve-Ellis.jpg|right|frame]]

[[File:lighterstill.jpg]][[File:Undertow-by-Steve-Ellis.jpg|right|frame]]

*[http://en.wikipedia.org/wiki/19th_century 1817]

*[https://en.wikipedia.org/wiki/19th_century 1817]

==Definitions==

==Definitions==

*1: the current beneath the [[surface]] that sets seaward or along the beach when [[waves]] are breaking upon the shore

*1: the current beneath the [[surface]] that sets seaward or along the beach when [[waves]] are breaking upon the shore

*2: an underlying current, [[force]], or tendency that is in [[opposition]] to what is apparent

*2: an underlying current, [[force]], or tendency that is in [[opposition]] to what is apparent

==Description==

==Description==

'''Undertow''' is a subsurface [[flow]] of [[water]] returning seaward from shore as result of [[wave]] action. This type of shore current can play a role in material deposition such as creating [http://en.wikipedia.org/wiki/Sand_bar sand bars].

'''Undertow''' is a subsurface [[flow]] of [[water]] returning seaward from shore as result of [[wave]] action. This type of shore current can play a role in material deposition such as creating [https://en.wikipedia.org/wiki/Sand_bar sand bars].

Undertows are below-surface rushes of water returning to [[sea]] after the water comes ashore as breaking [[waves]]. If there is an area under the waves where water can [[flow]] back out to sea more easily (such as a break in a sand bar) then a narrow [http://en.wikipedia.org/wiki/Rip_current rip current] can form. (A rip current is much more [[powerful]] and thus more [[hazardous]] to inexperienced people than ordinary undertow.) If however there is no [[weak]] point in the surf line, then the water that has run up onto the beach simply [[flows]] back out to sea under the waves, forming a simple undertow.

Undertows are below-surface rushes of water returning to [[sea]] after the water comes ashore as breaking [[waves]]. If there is an area under the waves where water can [[flow]] back out to sea more easily (such as a break in a sand bar) then a narrow [https://en.wikipedia.org/wiki/Rip_current rip current] can form. (A rip current is much more [[powerful]] and thus more [[hazardous]] to inexperienced people than ordinary undertow.) If however there is no [[weak]] point in the surf line, then the water that has run up onto the beach simply [[flows]] back out to sea under the waves, forming a simple undertow.

There is a popular misconception that the undertow is responsible for many [http://en.wikipedia.org/wiki/Drowning drownings] by somehow pulling people vertically down, so that they are then held under the water [[surface]]. While people can drown in any body of [[water]], even a puddle, undertow itself is relatively harmless; the great [[majority]] of drownings near the beach happen because people get caught in a [http://en.wikipedia.org/wiki/Rip_current rip current] which draws them out to [[sea]], and they are either poor swimmers or do not [[understand]] how to [http://en.wikipedia.org/wiki/Rip_current#Escaping_a_rip_current get free from a rip current].  

There is a popular misconception that the undertow is responsible for many [https://en.wikipedia.org/wiki/Drowning drownings] by somehow pulling people vertically down, so that they are then held under the water [[surface]]. While people can drown in any body of [[water]], even a puddle, undertow itself is relatively harmless; the great [[majority]] of drownings near the beach happen because people get caught in a [https://en.wikipedia.org/wiki/Rip_current rip current] which draws them out to [[sea]], and they are either poor swimmers or do not [[understand]] how to [https://en.wikipedia.org/wiki/Rip_current#Escaping_a_rip_current get free from a rip current].  

[[Category: General Reference]]

[[Category: General Reference]]