When they found the man he was hypothermic.
After being treated at the scene, he was winched off the bank and flown to Waikato Hospital.
The man, who was hunting by himself, told Fairfax he feared for his life.
"I knew I was in trouble, I knew I was going to [activate] my locator beacon and I knew the best chances of me getting help is if I'm visible from the air."
The man had stalked and killed a deer in rough terrain when he slipped and stabbed himself while cutting up the deer.
"I got up, pulled the knife out and then I felt a really warm sensation going through my body which I thought [was] a bit weird and then I looked down and blood was just pouring out," he told Fairfax.
Thoughts of his wife and four children quickly flooded into his mind.
Tying a tourniquet around his leg he found his way to a nearby river where he set off the emergency beacon.
"I got myself in a comfortable position because I was dizzy already and my heart was going 100 miles an hour and then I activated the beacon.
"I thought first things first, I need to stop the bleeding and calm the heart rate down.
"[I thought] if I cool down my leg, then the vein would hopefully cool down and shrink and the blood would start clotting," he told Fairfax.
Taking out a strobe light and torch, the man set an alarm for every seven minutes where he would loosen the tourniquet to release blood and take a bite of his muesli bar and a sip of water.
He was on the verge of losing consciousness when he heard the rescue helicopter approaching.
"I can't thank them enough - they were amazing."
The man was released from hospital on Sunday morning. Doctors told him if the blade had sunk 1cm further it would have cut a main artery and killed him.
He told Fairfax he wanted his tale of survival to encourage other hunters like himself to take safety seriously.
"I think the most important thing to have is a beacon - accidents do happen. You're not invincible.
"She'll actually not be okay. Be prepared, your life is worth spending a few dollars protecting."