Under Sydney Harbour Bridge, 23 July 2013.
See Google Earth 33°51'11.47" S 151°12'34.87" E

New colours after dry dock fitout
See http://www.shipspotting.com/gallery/photo.php?lid=1815545

IMO number : 9188594
Name of ship : SEAHORSE MERCATOR (since 01-11-1998)
Call Sign : VHN8774
Gross tonnage : 212 (during 1998)
DWT : 60
Type of ship : Training Ship (during 1998)
Year of build : 1998
Flag : Australia (during 1998)

RAN Newsletter 1998 states : Provides support to the RAN's Navigation Faculty. The name honours the Flemish chartmaker who invented the Mercator Projection Chart which is well-known to all navigators. She is based on the highly successful 23 ship Pacific Patrol Boat class built by Tenix. See http://en.wikipedia.org/wiki/Pacific_class_patrol_boat

SEAHORSE MERCATOR trains overseas mariners as well as RAN personnel and carries all modern state-of-the-art navigation equipment to teach the procedures for coastal navigation, pilotage, and is compatible for normal naval bridge training management and watch-keeping skills.

Operated by Serco company Defence Maritime Services (DMS)