Arwen's meanderings

Hi everyone and welcome to my new blog. My name is Steve and i am the lucky owner of a John Welsford designed 'navigator' named Arwen. I built her over three years with the help of my father, father-in-law and two children. She was launched in August 2007 at Queen Anne's battery marina in the barbican area of Plymouth. This blog is a record of our voyages together around SW England.
Arwen has a YouTube channel of her own. Search "plymouthwelshboy".






Thursday, 23 January 2014

More about the Cook Straits

Having read about Grant’s exploits sailing across the Cook strait, the geographer in me thought……..”Um , I wonder what that entails?”
It would seem the strait is between the north and south island of New Zealand, about 20 odd kilometres at its narrowest point (15 miles in old money?). Wikipedia said it is considered “ one of the most dangerous and unpredictable waters in the world”. 
Sounds intriguing I thought!
Apparently strong tidal flows are one issue along with the bizarre fact that if it is high tide at one end of the strait, it will simultaneously be low tide at the other end. That caused me some head scratching! Somewhere low water and high water have to meet!!
A quick check and it seems there is zero height change in the middle.  Tidal surges should flow one direction for six hours and then the reverse direction for six hours but in stormy weather this pattern can be severely disrupted with tidal flows going the same direction for several hours more than it should. Coupled with broken water caused by differing warmth currents along the submarine canyons this place probably deserves its fierce some reputation. 22 kilometres doesn't sound much until you factor in everything else and then........well quite some undertaking. 
Well done Grant!
Steve 

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