Camping on an island on a large lake in Me. The island is approx. 1/2 long by 1/4 wide.We like to take a boat trip to a cove on the SW of the lake to watch sundown and have a cocktail. On are way back in the dark we decide to take a different route around the N end of the island to our sight. In doing so we would pass 2 campsites on that side . As far as we knew the sites were empty since the campground closer earlier in Sept. We were 100 yds. from the 1st site and we notice brillant blue 'Globes' zipping through the, dropping to the ground the shooting up 20-30 ft. Al 3 of use saw them and the only commment was " What *** **** is that ?". We watched for approx 5 min. then sped around the island to our site.Pertinert Info. - wWhen we arrived at our site we made dinner and then sat by the fire without discussing it at all - I would estimate the globes to be the size of soccer or basketball and est. 12-15 of them.- The next morning we decided to hike to the site on the other side of island. The site is grassy, grass about 4 in. high. In this large area 50'X 70' there was not an undistrubed blade of grass ! No footprints. NOTHING !We have camped and fished on this island for the pass 12 yrs. Since the incident the driver of the boat will not get within 1/2 mile from that site after dusk.