Carrying about 30kg of fishing gear in a pack, Mr Prentice said he free-fell 8m before "bouncing" and falling another 8m, landing on his back on volcanic rock.
"I genuinely thought I was going to die," he said.
"All I could see was the sky above with the terrible sound of crashing boulders ringing in my ears...The most punishing thing was the sound when those boulders went, it was the sharp banging of rocks - I'll never forget it."
Mr Prentice had been "caught up" on the edge of another bluff, and said if he had fallen from that one he didn't think he would have survived.
When he came to, Mr Prentice said "it was the greatest feeling on earth knowing I still had movement in my toes".
His friends, who had not fallen, rang the Northland Rescue Helicopter which attended the scene within an hour.
The rescue crew winched Mr Prentice off the rocks and transported him to hospital.
They found out he had sustained several broken vertebrae on his lower back, a 50mm puncture wound next to his spine from a knife he was carrying, and bumps and bruises to his limbs.
"There's a sense of relief with every thump of the chopper blades as it nears you from afar," Mr Prentice said.
"The fearless and confident nature of the team was admirable, and had a contagious effect, I felt like everything was going to be okay.
"I have a tremendous amount of admiration for the Northland rescue team.
"I struggle for words to show the level of appreciation I have."
Despite trouble with the bone in his left elbow, Mr Prentice has almost made a full recovery.
He said he was planning a trip back to Northland in November "to conquer my fear".
