The man got his dog safely onto the dingy but could not get himself out of the water.
"I managed to grab a rock, was too exhausted to pull myself up so I got the phone out and rang 111," he said.
"I have been on the water all my life and only started to use the life jacket 30 years ago, and man alive I couldn't believe how it kept my head above the water…it saved my life."
After being rescued he was taken to Wairau Hospital.
"I was out in the water for over an hour, I can't swim and if it wasn't for my life jacket I would have drowned."
Area prevention manager Senior Sergeant Peter Payne said the man did all the right things.
"Having a cellphone in a watertight bag and wearing a life jacket most certainly saved this man's life, this could have easily ended tragically.
"Even the most experienced boaties can get into trouble out on the water as conditions change rapidly and as we head into summer I would encourage everyone to take a leaf or two out of this man's book."
The dog was safe and well.
"The pooch curled up in a jacket on board the Coastguard vessel and fell asleep as soon as it was rescued."