That happened on a hotel beach on Cape Cod one foggy summer night.
It was me with 3 green glow sticks tied to the bottom of my kite.
everybody at breakfast the next morning was talking about the UFO they saw...
My sighting was in the company of two level headed private pilots and lasted long enough that we could discern no simple explanation. The height ruled out a kite. It was against the prevailing wind, which ruled out it being a balloon. And it moved too slowly and without the lights required of an ordinary civil aircraft. And it was too large to be a satellite. I call it unknown.