re: Have you ever saved anyone from certain death?

Three for sure.
In 1990’s a tug sank in the Mississippi River, one was in the tug when it went down. The tug was lifted months later, his body recovered.
One guy was beached on a bulbous bow of a ship docked. Another’s body was floating face down. A third guy, was on the rudder of a ship, these three were within 40 yards of each other. I took a life ring, casting it out to the guy on the rudder, getting it as close as I could. He was in shock just yelling out. I finally decided to hit him with the life ring, the water was cold and with him in shock, my only option. It hit him, I said a few choice words, he grabbed it, I pulled him to the dock. Got him up. I had a small boat going around to the outside of the dock, they got the guy on the bow of the ship. The body floating, it was recovered around an hour later, right above the I-10 bridge.