The requested vessel with name SEIYU MARU and MMSI:0 and IMO:5319042 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
SEIYU MARU 9682174 431004475 >JP TXD OFF Dec 13, 2017 21:25 UTC
SEIYU MARU N/A 431002433 > JP KNM KH Dec 13, 2017 07:30 UTC

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