Sydney Harbour, passing Goat Island. 3 November 2017.
Vessel at 33°50'58.84" S 151°11'46.16" E

Marine Traffic data: (Note name change indication, as on bow)
SEAHORSE MERCATOR (Ship name as reported by AIS: MERCATOR 1)
IMO: 9188594
MMSI: 503334000
Call Sign: VHN8774
Flag: Australia [AU]
AIS Vessel Type: Military Ops
Gross Tonnage: 212
Deadweight: 60 t
Length Overall x Breadth Extreme: 32.5m × 8.21m
Year Built: 1998

Navigational training vessel operated by Defence Maritime Services under contract to the Royal Australian Navy (RAN). She is a modified version of the Pacific class patrol boat design and is based at HMAS Waterhen in Sydney

She trains RAN personnel and sailors from other navies in coastal navigation, ship handling and watch keeping procedures.