RE: Gut Hook Knives
I have had a Schrade "Old Timer" with gut hook for over 15yrs and a folding large Seatbelt Cutter which I used most, but not all the time.
1. Run you finger along the breastbone until you can feel the end of it. Pinch the skin away from the body so you don't puncture the intestines. Make a shallow cut just long enough to insert the first two fingers of your other hand.
2. Form a V with your first two fingers and maintain upwards pressure. Guide the blade between your fingers with the cutting edge up. Cut through the abdominal wall back to the pelvic area.