The 44-year-old has launched himself into churning seas, boggy ponds and wildife-rich rivers whatever the weather.
And fulfilling his pledge has meant making a splash across the country from Somerset to the far west coast of Scotland in search of the perfect alfresco dip.
Mr Turner, from Great Yarmouth, ended his watery challenge at one of his favourite spots close to his home town's harbour on Wednesday – but still plans to pull on his trunks on Christmas Day and New Year's Eve.
'I have always swum outdoors and when I moved to Great Yarmouth so close to the beach I decided to swim as much as I could,' he said.
'Then one year I found I had swum for two months, then it built up to three months. Then this year, almost without thinking, it got to five months and I thought 'Let's see how it goes through November and if I can make it to six months'.'
He added: 'Some of my friends think that I am a bit obsessive and to some extent I have been but I have never not enjoyed a swim and you only regret the ones you did not do.'
To qualify, a swim had to be at least 50m, although some were as long as two miles. In all 183 days he clocked up hundreds of swims, and experienced close encounters with, among others, seals, pike, swans and jellyfish.
However, Mr Turner, a reporter for BBC Radio Norfolk and member of the Caister lifeboat crew, stressed that while he was a passionate advocate of the joys of wild swimming he was equally vehement about safety.
Tides, currents and hidden dangers were all concerns and it was important to work out how to get out of the water before you got in, he said. He advised never swimming alone and to join organised swims at places like Fritton Lake.
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