3 friends and i were swimming in sweetwater lake and all noticed two towers with one light rise above the horizon, over the course of a number of minutes more lights were turned on and a third tower rose making a grid-like pattern of 3 towers with three lights each. this brightly illuminated the sky for a short number of minutes. after illuminating the sky there was a trail of mist or steam left in the sky and all 3 towers of lights disappeared beyond the horizon, shortly after the middle tower rose back up, with only the top light on, and once again disappeared shortly after. initially, the 4 of us believed the lights to be fireworks, but then did not act at all like conventional fireworks. it should also be noted that there was very little or no sound associated with the event.