Ferrylines.com constantly check 275 operator websites. We would like to point out 4 operators to you who show their current ship position on a map. It is a nice appetizer for web visitors:

Hurtigruten (N, along the coast): current ship position - ship web cams
Mols Linien (DK, inter island traffic): current ship position
Bornholmstrafikken (DK, Bornholm): current ship position
AG Ems (D, Borkum): current ship position