It was later discovered that the compass can be set to any item or individual, and will then point there, rather than to the north, aiding in the finding of that item.
To set the compass the item or person it is to be set to must be in line of sight and easily discernable. Then a Knowledge: Navigation roll is made. (This is modified for lighting, and cover, as it is possible to set the compass to the 'wrong' thing)
Once the compass has been set, efforts to find the item it is set to are made at +4 to all relevant rolls as long as the compass can be referred to.