Icons are limited? Or is it possible to add icons?

When adding/modifying a waypoint you can select a matchingicon. However, the number of icons standard available in Explore do not match the real situation. For instance, when i make a waypoint to a ferry, i cannot select a matching icon.

So, my question is:

Can i add my own waypoint or is it possible to add waypoints from a (Garmin) library or such?