Some great suggestions, too bad,,,,
1) fireworks are illegal to possess here especially those types, also think there would be a possibility of a forest fire.
2) Dont really want to spend a night in 15 degree weather with the very likely possibility of snow, also the 4 legged predators in the area are feeding at that time! lots of wolves, couple bear and a cougar was spotted this year.
3) no kids(dogs are illegal in this area), got a couple kids you want to rent cheap for a week?
4) no water in the swamp, just very thick mud and cattails.

Im thinking head as far east of the island as possible and firing a couple marbles into the neighbours woods, followed by a several onto the back half of the island will move them. Too bad I figured this one out, going to have to stick someone else directly south of the island to intercept.