I assumed it was a low flying helicopter scanning the beach with a large spotlight because that is how it appeared to me. I stopped to watch it as it approached slowly from a distance of around a mile away. It wasn't until afterward that I realized that there was no sound as it came upon me. As it flew directly over me at a distance of around 80-100 feet, the light appeared to move up in the direction it was traveling and suddenly faded out with a afterglow of luminescence, like a large spotlight turning off. after that, it completely vanished, and there was absolutly nothing there, right before my eyes.