Seahorse Mercator is a 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 (naval base) in Sydney.

Design and construction

Seahorse Mercator is a variant of the Pacific-class patrol boat design. The ship has a displacement of 165 tons, a length of 31.5 m, a beam of 8.21 m, and a draught of 2.6 m. Propulsion is supplied by two Caterpillar 3304 diesels, driving two propellers. Maximum speed is 16 kn, with a range of 2880 nmi at 8 kn. Seahorse Mercator is run by a crew of five plus three instructors, and can carry up to eighteen trainees. Radars include a Furuno FE 606 navigation radar, and a Decca Bridgemaster ARPA navigation radar. The vessel is unarmed. Seahorse Mercator was built by Tenix Ship Building Western Australia for DMS at a cost of A$4 million. The vessel was launched on 15 October 1998. The Canadian Forces Maritime Command's Orca-class patrol vessels were built to a modified variant of Seahorse Mercator's design.

Operational history

Seahorse Mercator conducted sea trials during November 1998, with handover to DMS and the RAN on 26 November 1998 She was assigned to the naval base HMAS Waterhen (naval base), and replaced the Attack-class patrol boat HMAS Ardent (P 87) as the RAN's Sydney-based navigational training vessel in December that year. Since then she has mainly operated in the Sydney area and has trained RAN personnel and sailors from other navies in coastal navigation, ship handling and watch keeping procedures. Seahorse Mercator has a secondary role as a mine countermeasures craft.