Bay-class vessels have a displacement of 134 tons, are long, have a beam of, and a draught of. The propulsion system consists of two MTU 16V 2000 M70 diesel engines, supplemented by a VosperThornycroft bow thruster. The patrol boats have a maximum speed of, and a maximum range of. Each vessel is fitted with a 7.62 mm general purpose machine gun, and two Wiltrading Pursuit 640 vessels are carried for boarding operations. The sensor suite consists of a Racal Deccasurface search radar operating in the E/F and I bands, and a Wesmar SS 390E dipping sonar. A Bay class vessel has a crew of 12. The Bay class was built by Austal Ships. The eight ships were delivered over a period of 19 months, beginning in February 1999. The Bay-class design was used as the basis for the 14 larger s in use with the Royal Australian Navy, and the 10 patrol boats used by the Yemen Navy.
Operational history
The eight patrol boats are operated by the Customs Marine Unit of the Australian Customs Service. They are primarily used to patrol Australia's Economic Exclusion Zone, although they also operate in support of other Australian law enforcement and defence agencies, including but not limited to the Australian Federal Police, the Great Barrier Reef Marine Park Authority, and the Royal Australian Navy. Bay-class vessels often operate on border protection duties under Border Protection Command. The age of the vessels and resulting maintenance needs has seen a drop in the amount of time spent at sea, with other ships of the Customs Marine Unit forced to take up the slack.
Foreign service
Two Bay-class patrol boats have been gifted to the Sri Lankan Navy. Corio Bay was transferred on 30 March 2014, and Hervey Bay was handed over on 3 June that year. Originally renamed as SLNS Oshadi and SLNS Omaya, the patrol boats were recommissioned on 9 July as SLNS Mihikatha and SLNS Rathnadeepa. Another two were offered to the Malaysian Maritime Enforcement Agency in 2014. Arnhem Bay was handed over on 10 February 2015, and was renamed KM Perwira. Dame Roma Mitchell was transferred in May 2015, and renamed KM Satria.
Replacement
The Bay class were due to be replaced in 2010, but it was not until June of that year that a request for tender was issued for eight new, larger patrol boats. Austal received the tender for eight patrol boats on 12 August 2011. Construction of the vessels, designated the, started in 2012 with the keel of the first boat being laid in June 2012, and launched in January 2013. The new patrol boats entered service between March 2013 and September 2015, with the Bay class no longer in service with Australia.
Ships
ACV Roebuck Bay Active ACV Holdfast Bay laid up ACV Botany Bay laid up ACV Hervey Bay now SLNS Rathnadeepa ACV Corio Bay now SLNS Mihikatha ACV Arnhem Bay now KM Perwira ACV Dame Roma Mitchell now KM Satria ACV Storm Bay