Australia is a maritime nation. With an exclusive economic zone covering nearly nine million square kilometres, the Royal Australian Navy (RAN) has long depended on small, agile patrol boats to uphold sovereignty, protect fisheries, and support border operations. Since 1950, several generations of patrol vessels have carried the load, each replacing the last in a constant cycle of renewal.

This article traces the story of RAN patrol boats from the early post-war period through to the brand-new Arafura-class Offshore Patrol Vessels (OPVs) now entering service.

Stopgap Patrols: The 1950s–60s

In the years after WWII, the RAN did not yet have purpose-built patrol boats. Instead, older wartime craft carried the duties. Bathurst-class corvettes, originally designed as all-purpose escort vessels, were kept on in training and coastal roles. Likewise, Ton-class coastal minesweepers—small British-built ships—served in northern waters, including patrol and interdiction missions during the Indonesia–Malaysia Confrontation of the mid-1960s.

These experiences highlighted the need for a vessel designed specifically for constabulary work: fast, manoeuvrable, lightly armed, and capable of extended operations in remote northern waters.

Attack Class (1967–mid-1980s): The First Modern Patrol Boats

The RAN’s answer was the Attack class, the first Australian patrol boats designed for sovereignty and border protection rather than wartime escort duty. Twenty were built between 1967 and 1969, most in Queensland and South Australia.

Small but tough, the Attacks were about 32 metres long and instantly recognisable in northern ports like Darwin. Their roles included fisheries enforcement, customs patrols, and search-and-rescue. Several even served on Operation Cenderawasih patrols in Papua New Guinea.

By the mid-1980s the class had worn out. Some transferred to Papua New Guinea and Indonesia; one, HMAS Advance, survives today at the Australian National Maritime Museum in Sydney.

Replaced by: the Fremantle class.

Fremantle Class (1979–2007): A Bigger Hull, Longer Legs

With increasing demands in the 1970s, the RAN needed a patrol boat with greater endurance. The result was the Fremantle class, introduced from 1979. Fifteen were built: the first in the UK and the rest at Cairns.

At 41 metres, the Fremantles were bigger, with better sea-keeping and greater range, allowing them to stay at sea longer and cover more territory. They quickly became the backbone of northern patrol operations through the 1980s and 1990s.

The last two Fremantles decommissioned in May 2007.

Replaced by: the Armidale class.

Armidale Class (2005–late 2010s): High-Tempo Border Ops

Between 2005 and 2008, Austal delivered 14 Armidale-class patrol boats to the RAN. About the same size as the Fremantles, the Armidales were designed for high utilisation. Multi-crewing arrangements kept them on patrol almost constantly, supporting Operation Resolute, Australia’s border protection mission.

For over a decade the Armidales were the workhorses of the RAN, but the punishing operational tempo and age led to fatigue and reliability issues. By the late 2010s, the Navy looked to newer solutions.

Replaced by: progressively phased out in favour of Cape-class variants and, ultimately, the Arafura-class OPVs.

Cape Class & Evolved Cape Class (2017–present): Bridging the Gap

To ensure patrol capacity while the new OPVs were under construction, the RAN turned to a design already in service with the Australian Border Force: the Cape class.

• 2017: Two standard Capes (ADV Cape Fourcroy and ADV Cape Inscription) entered RAN service.

• 2020 onwards: The Evolved Cape class (ECCPB) followed—an upgraded design with improved systems, electronics, and crew accommodation. Initially six were ordered; by 2024 the fleet had grown to ten.

The Evolved Capes now form a vital part of the patrol force, handling day-to-day constabulary work alongside the larger new OPVs.

Role: replacing the Armidales and supplementing the incoming Arafura class.

Arafura Class OPV (from 2025): The Latest Generation

On 28 June 2025, the RAN commissioned HMAS Arafura, the first of the Arafura-class Offshore Patrol Vessels. These 80-metre ships mark a step change: larger than any earlier patrol boat, with a range of 4,000 nautical miles, modern sensors, a 25 mm main gun, and multiple RHIBs launched via stern ramp.

The design allows for modular “mission payloads,” including uncrewed systems, making the Arafura class adaptable for border protection, regional engagement, and humanitarian support.

The current plan calls for six OPVs in RAN service, operating alongside the Evolved Cape class.

Replacement Timeline at a Glance

• 1950s–60s: Bathurst-class corvettes, Ton-class minesweepers (stopgap patrols).

• 1967–mid-1980s: Attack class → replaced by Fremantle class.

• 1979–2007: Fremantle class → replaced by Armidale class.

• 2005–late 2010s/2020s: Armidale class → replaced by Cape & Evolved Cape class.

• 2017–present: Cape/Evolved Cape class → supplemented and progressively replaced by Arafura OPVs.

• 2025 onwards: Arafura class OPVs become the lead patrol force.

Today’s Fleet

As of September 2025, the RAN’s patrol boat fleet consists of:

• Evolved Cape-class patrol boats (ECCPBs): Ten in service, handling daily constabulary duties.

• Arafura-class OPVs: HMAS Arafura and HMAS Eyre now commissioned, with four more vessels under construction, set to become the backbone of future patrol operations.

Conclusion: From Modest Boats to Offshore Workhorses

From the modest Attack class of the late 1960s to the high-tech Arafura OPVs of today, RAN patrol boats have continually evolved to meet the challenges of Australia’s vast maritime domain. Each new class has extended endurance, improved technology, and delivered greater flexibility.

The mission, however, remains constant: to safeguard Australia’s borders, protect resources, and provide a visible naval presence in some of the busiest seas in the world.

Seacraft Gallery – July 2026