Blakey, who now works as a building company manager, had his bladder removed and had everything rewired and replumbed to create a false bladder inside his body using part of his large intestine. Once he'd recovered, the hard-case Yorkshireman, who has lived in New Zealand for the past 15 years, didn't fancy moping about, so he ran the 2009 Auckland Marathon, harking back to his running days when he ran the New York Marathon twice.
"Running that marathon was murder," he said in his broad accent. "I didn't want to drink too much before the race because I can't wee properly and I need to use a catheter too and that was not really an option in the middle of the race, so it was bloody difficult. I was so relieved to finish."
He expects he will feel the same next Sunday when he has safely negotiated the harbour crossing. Blakey is the first to admit that swimming really isn't his forte.
"The problem with my training is that as a Pom we grew up doing breaststroke. I go to the pool out west and see all these fit, slim-line Kiwis swimming all these lengths and here I am, a big fat Pommy bobbing up and down like a British bullfrog."
He reckons swimming 2.9km is at the limit of his ability.
"It's huge and I am bloody nervous. But it is another challenge. I'll be pleased if I don't finish last."
His humour is a long way from all the pain and heartache he and his family have suffered during his battle with cancer.
"There were some times when I'd wake up at three in the morning and be totally depressed about the whole situation, but that is the normal. I think it is my Yorkshire determination that helps me just get on with it."
Event organiser Scott Rice is amazed by Blakey's resilience.
"Mark is an inspirational character for us all to take motivation from. Often it seems to take a moment of adversity for someone to produce an extraordinary feat. Mark shows that anyone can achieve anything.
"Being active and healthy is so important to us all. Swimming is an ideal way to achieve that and the State New Zealand Ocean Swim Series is an achievable target for all."
Blakey has simple advice for people looking to overcome adversity in their own lives.
"Look for all options available and never give up. There are some clued-up people out there and there are a lot of ways to get rid of the cancer ... and on a personal level, stay positive, positive, positive. It is not easy, but when you get through it is a huge thrill to be able to live again."