Backwash

[GameOn]

Water current anomolies caused by either permanent current commonly found in rivers and creeks or temporary current like that caused by winds.  When the current is rapidly shifted; such as when it goes around a sharp bend in a river or accross any solid object like a submerged tree, stump, weed patch, or land point; an area of water on the down current side of the structure will swirl due to the water friction of the passing current.  The swirls may be obvious and swift or large and slow.  Floating debris will appear to move in the "wrong" direction of the surrounding current.  Or it may whirlpool, in the more swift backwash.