"It dawned on me I was underwater and I realised I also couldn't move my arms and legs. I really thought this was the end. I was a goner and I was going to drown."
Fortunately a doctor, a nurse and a firefighter were among those holidaying at the beach that morning.
"I mean, what are the odds of that? They got me out of the water using my board as a stretcher and got me stable and the doctor recognised I had broken my neck."
But heavy holiday traffic meant an ambulance would have taken too long, and the journey by road would risk further injury.
Instead a terrified Smith lay at the water's edge until the Westpac Rescue Helicopter arrived and he was flown to North Shore Hospital.
"At first I had no feeling in my arms and legs, then I got pins and needles in my toes that were so painful I felt I was being electrocuted.
"I was so glad when I heard the chopper arriving. The crew took control and if it hadn't been for them and the quick thinking of the people at the scene I might have died."
Westpac Rescue Helicopter advanced paramedic Russell Clark said things could have been fatal if experienced professionals had not been on the beach that day.
"I can't praise enough the actions of the people who were there on the ground," he said. "They did a great job until we got there and could airlift Mike out. Spinal cord injuries can be very difficult to deal with."
After two months in hospital Smith slowly moved from a wheelchair to learning how to walk again.