UFO or something else?

UFO or something else?
Location: folly beach south carolina 
Time: 10pm, Dec
Forgot to add time last post but is this a ufo of some sort  or a plane? Saw it flying for about 5 minutes in the sky and caught a little glimpse of the shape, looked greyish and geometric,then it came very low to the beach and completely illuminated the water staying in the same spot for about 2 minutes while shining the light on me and my date then moved on. It made no noise. Not sure if it was a ufo or just really odd aircraft. Thanks for any input.