The requested vessel with name SIVA and MMSI:0 and IMO:5246908 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
SIVA N/A 244090199 Oct 27, 2017 10:03 UTC
SIVA N/A 257084940 Nov 15, 2016 13:27 UTC

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