Armidale, named for the city of Armidale, New South Wales, is the lead ship of the Armidale class of patrol boats serving in the Royal Australian Navy (RAN).

The Armidale-class patrol boats are 56.8 metres (186 ft) long, with a beam of 9.7 metres (32 ft), a draught of 2.7 metres (8 ft 10 in), and a standard displacement of 270 tons.^[1] The semi-displacement vee hull is fabricated from aluminium alloy, and each vessel is built to a combination of Det Norske Veritas standards for high-speed light craft and RAN requirements.^[2] The Armidales can travel at a maximum speed of 25 knots (46 km/h; 29 mph), and are driven by two propeller shafts, each connected to an MTU 16V M70 diesel.^[3] The ships have a range of 3,000 nautical miles (5,600 km; 3,500 mi) at 12 knots (22 km/h; 14 mph), allowing them to patrol the waters around the distant territories of Australia, and are designed for standard patrols of 21 days, with a maximum endurance of 42 days.^[3][2]

The main armament of the Armidale class is a Rafael Typhoon stabilised 25-millimetre (0.98 in) gun mount fitted with an M242 Bushmaster autocannon.^[3] Two 12.7-millimetre (0.50 in) machine guns are also carried.^[4] Boarding operations are performed by two 7.2-metre (24 ft), waterjet propelled rigid-hulled inflatable boats (RHIBs).^[2] Each RHIB is stored in a dedicated cradle and davit, and is capable of operating independently from the patrol boat as it carries its own communications, navigation, and safety equipment.^[2][5]

Each patrol boat has a standard ship's company of 21 personnel, with a maximum of 29.^[3][2] The Armidales do not have a permanently assigned ship's company; instead, they are assigned to divisions at a ratio of two vessels to three companies, which rotate through the vessels and allow the Armidales to spend more time at sea, without compromising sailors' rest time or training requirements.^[2][6] A 20-berth auxiliary accommodation compartment was included in the design for the transportation of soldiers, illegal fishermen, or unauthorised arrivals; in the latter two cases, the compartment could be secured from the outside.^[7] However, a malfunction in the sewerage treatment facilities aboard HMAS Maitland in August 2006 pumped hydrogen sulfide and carbon monoxide into the compartment, non-fatally poisoning four sailors working inside, after which use of the compartment for accommodation was banned across the class.^[6][7]

Armidale was constructed by Austal at their shipyard in Henderson, Western Australia.^[1] She was commissioned into the RAN in Darwin on 24 June 2005.^[1]

Armidale is assigned to Attack Division, is based in Darwin, and performs border protection and fisheries protection patrols.