More info on the vessel can be found here:
https://balticworkboatsus.com/vessel/pilot-1700-wp/
Vessel name: Polaris ; Year built: 2012 ; Flag: Netherlands ; Homeport: Rotterdam Length: 81.2m X 13.3m ; GRT: 2501 ; Callsign: PBZN ; MMSI:245142000 ; IMO: 9496915 Type: Special Vessel / Pilot Ship A "Pilot Ship / Pilot Vessel" is a "special type" of ship in which it accommodates a certain and limited Marine Pilots (Sea, River, Harbor Pilots), it also carries small boats/crafts that are used to tender services to and from the Pilot ship. In a Pilot Vessel, the Pilots can take their time...
NANIWA (Pilot Vessel) IMO: - MMSI: 431007094 Call Sign: - Flag: Japan [JP] AIS Vessel Type: Other Gross Tonnage: - Deadweight: - Length Overall x Breadth Extreme: 18m × 4m Year Built: - Status: Active Voyage Info https://www.marinetraffic.com/en/ais/details/ships/shipid:3738287/mmsi:431007094/vessel:NANIWA