Tidal race
{{short description|Fast-moving tidal flow passing through a constriction, forming waves, eddies and strong currents }}
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File:Lunga and the Grey Dog.jpg from Scarba, across Scotland's "Grey Dog" tidal race]]
Tidal race or tidal rapid is a natural occurrence whereby a fast-moving tide passes through a constriction, resulting in the formation of waves, eddies and hazardous currents. The constriction can be a passage where the sides narrow, for example the Gulf of Corryvreckan and the Saltstraumen maelstrom, or an underwater obstruction (a reef or rising seabed), such as is found at the Portland Race in the United Kingdom.
In extreme cases, such as Skookumchuck Narrows in British Columbia, through which tides can travel at more than 17 knots (31.484 km/h), very large whirlpools develop, which can be extremely hazardous to navigation.
Notable tidal races
- Cape Reinga in New Zealand
- Skookumchuck Narrows in British Columbia, Canada
- The Bitches in Wales, United Kingdom"[http://www.ffynnongron.com/leisure-activities-eat-drink/nature.html Nature]"[http://www.the-bitches.co.uk/ The-Bitches.co.uk][http://www.ukriversguidebook.co.uk/swales/bitches.htm UK Riversguidebook][http://www.canoewales.com/the-bitches.aspx CanoeWales] {{Webarchive|url=https://web.archive.org/web/20140911215144/http://www.canoewales.com/the-bitches.aspx |date=2014-09-11 }}"[http://www.ramseyisland.co.uk/ramsey-and-the-outer-islands/the-bitches-rocks/ Bitches and Tides]"
- Falls of Lora in Scotland, United Kingdom
- Portland Bill on the Isle of Portland, United Kingdom
- The Alderney Race (12 knots+) between Alderney and La Hague, Normandy, France
- The Raz de Sein in western Brittany, France
- The Fromveur Passage in western Brittany, France
- Horizontal Falls in Western Australia, Australia
- Naruto Strait between Shikoku and Awaji Islands, Japan
- Reversing Falls in Saint John, New Brunswick, Canada
See also
- {{annotated link|Gut (coastal geography)}}
- {{annotated link|Rip current}}
- {{annotated link|Tidal bore}}
Sources
{{Reflist}}
{{Physical oceanography}}
{{Underwater diving|scidiv}}
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{{DEFAULTSORT:Tidal Race}}