The requested vessel with name CHOUN MARU and MMSI:0 and IMO:5123742 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
CHOUN MARU 9820611 431009647 >JP KZJ Feb 25, 2018 03:39 UTC
CHOUN MARU N/A 431401108 Apr 23, 2017 06:38 UTC
CHOUN MARU NO.7 N/A 431004202 Feb 25, 2018 11:39 UTC

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