The requested vessel with name GREIFSWALD and MMSI:0 and IMO:5135848 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
GREIFSWALD 8311912 370492000 POTI Jan 16, 2018 16:57 UTC

Also, you may try to find the vessel in our comprehensive Vessels Database or track this ship on the map.