The requested vessel with name SEISHU MARU NO6 and MMSI:0 and IMO:6509761 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
SEISHUUMARU NO31 N/A 431007071 May 09, 2017 03:48 UTC

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