translucent football seen over city airport

I was in Junior high school, and our school was on a high hill overlooking the city. I could see across all of Traverse city all the way to the airport. I first seen something that was almost translucent but football shaped. the day was cloudy and it was fall chilly day. I asked a friend if he seen that thing over on the horizon. He looked a bit and I pointed it out. He did see it, and we both had a wierd feeling. It wasn't a helicoptor or a plane. It did spend some time moving up and down, and around the same area. Now we do have a coast guard station at the airport, and a kid who saw us looking started looking for the object. we pointed it out to him, and he just couldn't see it.
I could still see the shifting of it and moving up and down. the one kid who just couldn't see it turned sour grapes and said it was a coast guard helecoptor practicing his touch and goes. I guess It could have been, but I seen something that looked like a translucent football. Almost like a floater in your eye. One other kid seen it and a few others around seemed to be watching the area but didn't say anything.
To this day I have asked a few people what they thought, and nobody has ever heard of a football translucent colored ship that was seen around traverse city airport, and I probably never will.
Date is approximate.  PD