The requested vessel with name YOSU and MMSI:0 and IMO:5396399 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
YOSU GAS 9016739 440831000 YOS_KR Jan 31, 2018 21:45 UTC
YOSUN N/A 271040493 Nov 02, 2017 16:17 UTC

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