Another major consideration is your immediate disorientation. I had the chance to train in a helicopter ditching simulator. Imagine suddenly being plunged into cold darkness at angles worthy of a carnival ride! I once 'rescued' a man who panicked. He was backing a boat down the ramp and hit the gas instead of the brake. We watched the boat,airstream trailer and truck go in. As he screamed in terror, I waded out,opened the door and walked him to shore. I carry the spring punch also. If life is worth lifeboat matches vs. paper , then look for lifeboats in all your gear.