Report 43519: Night fishermen startled while in their boat at Tippy Dam Campground

We were on our yearly camping trip to Tippy dam pond, I believe its outside of Manistee. Its very remote, you have to travel down many back dirt roads to get to the campground .We have went camping up at Tippy dam for years, always in the spring to do a lot of fishing, day and night fishing. It was after midnight when we got up there in 2012 and we set up tents and the girls all went to sleep. Me and my brother and 12 yr old son took the boat out for some night fishing. We got back into this cove, the Tippy dam pond is huge, they call it the flooded forest. Its beautiful you could swear you were in Canada, very hilly. Huge hills back up to the water but all forest in every direction, very very remote. We were fishing sitting in the dead quiet when all of a sudden we were scared out of our minds!!! A huge rock that must have been the size of a bowling ball was thrown at are boat. At first we blew it off as if it were a fish jumping all though the distinct sound of a round ball hitting water is unmistakeable. So about 3 mts. went by when another one was thrown even closer to the boat. There was no way this was a fish, we shined a flashlight through the woods and could hear something moving fast thru the brush but could not make out what it was ..this area we were fishing is so remote there is no way any human would be out there let alone in the middle of the night ..I've never seen my brother scared, we are Michiganders, we deer hunt yearly spend days in the woods but we were scared that night. Something did not want us in that lil cove fishing and it was hurling huge rocks at us ta get us outta there and it worked lol. We started the boat and flew back to camp and woke the girls....