The more time you spend on the water throughout your life, the more likely you are to help or be helped by other boaters, both power and sail.
As far as actually saving lives, in most cases it is very difficult to know that. When something goes wrong on the water, whether you run out of gasoline or start taking on water or capsize, it may not necessarily seem like a life-threatening situation at the time, but it could very easily turn into one.
So, "potentially" sailors have saved many lives just by going to the aid of others in distress.
That is why I have ALWAYS made it a law that I NEVER go out alone. I could not tell you how may times I have had to go for help or had help gotten for me. Last time newbie went out with I life jacket that did not fit, would not close. He fell off and boat was drifting faster than he could swim and other person could not right the boat alone first few trys. I got him on the 4.3 and got him close to swim over and help. He didn't make it. Got him on again and dropped off by boat where he could hold on. I went to shore for help. Before I got back boat owner had righted boat. I could figure out why he was zig zagging? When I got close he said I can't find Carlos. With ill fitting vest his head was barley above the chop. We started a grid search for him. After 45 min and almost calling the Coast Guard, we found him, he was exhausted and it took all my strength to get him on (close to 290 lbs). It could have been REAL bad.
Doug
