I have to say, the one time, I was ever in distress, flares were what got the Coast Guard to us. We were sailing at night in about 25 knots of wind, and got dismasted when a stay broke. Of course, the VHF antenna was on top of the mast and ten or fifteen feet below us when we needed to call for help. The handheld didn't reach anyone.
We fired two flares, and a few minutes later, I see a barge and tow heading directly for us. I fired the last two flares at the barge because I thought he didn't see us and thought we were about to be run over. He had actually seen the first two flares and was coming over to investigate. He called the Coast Guard for us who came out.
I don't know who else reported them, but when they arrived, the Coast Guard asked us how many flares we had shot several times, confirming it was us who shot all four flares.