Click the map below to see the last know position of Shadowfax.
The boat has an AIS (automatic identification system), which takes a position and plots it to a central worldwide database called Marine Traffic. All commercial ships have this and some private vessels also. Practically speaking it means that we can see other ships coming and they can see us, even in thick fog! It also means than anyone else on land can see where we are, providing we are in range of a transmitter!