"Null Island" is a ocean buoy at zero-latitude/zero-longitude in the Gulf of Guinea off the west cost of Africa.

This an odd case of dereferencing a NULL Pointer. Some Apps default to this valid physical location (It has become a tourist destination for the brave or foolish) leading to strange directions and distance calculations.

If need to have a default make sure it is not a valid location such as using +91 or -181 (out of range values).