You need to be a bleacher creature to get this one. It is below the seats.
However, with all the metal you might be best off locating it from above and then going underneath to find it.
I checked the coordinates on 4 separate days at 4 separate times and all the readings came in very close to one another.
This one is fun but not easy, (most likely).
I am telling you right now that it is magnetic, however, everything you can see is metal so not sure how much that helps.