Austal Evolved Cape-class patrol boat

History

The Evolved Cape-class patrol boat is an Australian patrol vessel developed by Austal for the Royal Australian Navy. It is an upgraded development of the Cape-class design and was introduced as an interim patrol capability while the Navy prepared for the Arafura-class offshore patrol vessels.

The class supports border protection, maritime constabulary, law-enforcement support and other naval missions. Compared with the original Cape class, the Evolved Cape design provides accommodation for up to 32 personnel, improved quality-of-life systems and advanced sustainment intelligence systems.

Ten Evolved Cape-class boats were ultimately built at Austal's Henderson shipyard in Western Australia. The final two vessels, HMAS Cape Spencer and HMAS Cape Hawke, were commissioned at HMAS Cairns on 27 August 2026, completing Project SEA 1445 Phase 1.

Development and construction

In April 2020, the Australian Department of Defence awarded Austal Australia a contract valued at A$324 million to design and build six Evolved Cape-class patrol boats. The project was intended to replace the Armidale-class patrol boats and provide an interim capability before the introduction of the Arafura class.

The first vessel, ADV Cape Otway, was delivered to the Royal Australian Navy in March 2022 and reached its home port at Cairns in June 2022. The second vessel, ADV Cape Peron, was delivered in August 2022. Other vessels in the initial group included ADV Cape Naturaliste, ADV Cape Capricorn, ADV Cape Woolamai and ADV Cape Pillar.

A further order for two boats was placed in 2022. Austal subsequently stated that later contract extensions in 2022 and 2024 expanded the program to ten vessels. All ten were designed and constructed at Henderson, Western Australia.

The tenth Evolved Cape-class patrol boat, Cape Hawke, was delivered to Defence Australia before the final commissioning ceremony. HMAS Cape Spencer and HMAS Cape Hawke were commissioned together at HMAS Cairns on 27 August 2026. Their entry into service marked completion of the Evolved Cape-class construction and commissioning program under Project SEA 1445 Phase 1.

Design

The Evolved Cape class is based on Austal's aluminium monohull Patrol 58 design. Austal describes the Evolved Cape as an improvement over the original Cape-class patrol boat, with changes intended to increase operational capability, crew capacity and habitability.

Hull and accommodation

The latest reported overall length is 58.1 m, while an earlier published technical description gives 57.8 m. The latest report gives a beam of 10.6 m, compared with 10.3 m in the earlier description. The earlier technical description also lists a draught of 3 m. The aluminium monohull accommodates a crew of about 32 personnel and provides space for embarked law-enforcement personnel and detainees.

Habitability improvements include increased amenities and improved quality-of-life systems. The design also incorporates a holding cell intended to provide better accommodation for detainees while at sea.

The vessel's motion-control equipment includes two 3.25 m² roll fins and two 4.5 m² trim flaps. Two 7.3 m Gemini rigid-hull inflatable boats can be carried for boarding, interception and other small-boat operations.

Propulsion

Each Evolved Cape-class patrol boat is powered by two Caterpillar 3516C V-16 four-stroke diesel engines. A published technical description rates each engine at 2,525 kW at 1,800 rpm. The engines drive two fixed-pitch propellers through ZF 9055A gearboxes. An HRP 2001TT bow thruster rated at 160 kW assists low-speed manoeuvring.

Recent reporting gives a maximum speed of about 26 knots, while an earlier technical description lists 25 knots. The class has a range of more than 4,000 nautical miles; Austal states that Patrol 58 vessels can sail about 4,000 nautical miles before refuelling, while another technical source specifies more than 4,000 nautical miles at 12 knots.

Navigation, communications and support systems

The vessels incorporate secure and non-secure voice and data communications using VHF, UHF and satellite communications. The integrated bridge arrangement includes electronic chart display and information systems, gyrocompasses, secure automatic identification system transponders, radar, differential global positioning systems and voyage data recorders.

The class also incorporates advanced sustainment intelligence systems. Austal identifies these systems, together with improved quality-of-life arrangements, as important differences between the Evolved Cape design and the original Cape class. Additional technical information is available from the Austal Patrol 58 description and the Evolved Cape technical overview.

Armament and boats

Each vessel is armed with two 12.7 mm machine guns. The two embarked rigid-hull inflatable boats support boarding and interdiction operations, including the interception and investigation of suspicious vessels.

Operational history

The Evolved Cape-class boats entered Royal Australian Navy service as an interim patrol capability for maritime security and constabulary tasks. Their roles include border protection, maritime surveillance, law-enforcement support and other naval missions.

The class operates from Cairns, Queensland, and maintenance support is associated with the Regional Maintenance Centre North East in Cairns. Completion of the ten-boat program in 2026 provided the Navy with the full planned Evolved Cape-class fleet while the wider transition to the Arafura-class offshore patrol vessel proceeded.

Operators

• Royal Australian Navy: Ten Evolved Cape-class patrol boats were built for Australian Defence requirements and delivered for Royal Australian Navy service. The final two vessels were commissioned on 27 August 2026.

Specifications (Evolved Cape class)

General characteristics

• Type: Patrol boat
• Hull: Aluminium monohull
• Length: 58.1 m in the latest reporting; an earlier technical description gives 57.8 m
• Beam: 10.6 m in the latest reporting; an earlier technical description gives 10.3 m
• Draught: 3 m in the earlier published technical description
• Crew capacity: About 32 personnel
• Boats: Two 7.3 m Gemini rigid-hull inflatable boats

Powerplant and performance

• Engines: Two Caterpillar 3516C V-16 four-stroke diesel engines
• Engine output: 2,525 kW each at 1,800 rpm in the published technical description
• Transmission: Two ZF 9055A gearboxes
• Propellers: Two fixed-pitch propellers
• Bow thruster: HRP 2001TT, 160 kW
• Maximum speed: About 26 knots in recent reporting; an earlier technical description gives 25 knots
• Range: More than 4,000 nautical miles; one technical description specifies this range at 12 knots

Armament

• Machine guns: Two 12.7 mm machine guns

Related equipment

• Cape-class patrol boat: The original Austal Patrol 58 design from which the Evolved Cape class was developed.
• Arafura-class offshore patrol vessel: The offshore patrol vessel program for which the Evolved Cape class was intended to provide an interim bridging capability.