The requested vessel with name KRONBORG and MMSI:0 and IMO:7300734 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
KRONBORG 9316593 636013100 ES FUE > ES SCT Jan 24, 2018 00:09 UTC
KRONBORG-R 6617829 219566000 NEW AMSTERDAM Dec 02, 2012 14:27 UTC

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