The requested vessel with name TRIPOLIS and MMSI:0 and IMO:6421074 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
TRIPOLIS N/A 205541790 AMSTERDAM Feb 18, 2018 12:46 UTC

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