HMAS Acute
Attack Class Patrol Boat
Patrol Boat
Evans Deakin and Co
26 August 1967
26 April 1968
06 May 1983
Transferred to Indonesian Navy
Dimensions & Displacement
Displacement 146 tons
Length 32.76 metres
Beam 6.2 metres
Draught 1.9 metres
Speed 24
Crew 21
Machinery Twin Paxman Diesels
  • 1 x 40mm Bofors
  • 2 x .50 calibre M2 Browning machine guns
HMAS Acute Badge

HMAS Acute commissioned in Brisbane on 26 April 1968. She was one of twenty Attack Class patrol boats ordered for the RAN in November 1965. The Attack Class was equipped with high-definition navigation radar, magnetic compasses, an echo sounder and air conditioning for service in northern Australian waters. Their primary role was to conduct patrol work in Australian territorial waters.

HMAS Acute's bell
HMAS Acute's ship's bell is now on display in the Naval Herritage Collection.

After a brief work up, Acute sailed south to Sydney where she continued working up in the Broken Bay area in company with her sister ship, HMAS Lae. Following a period of defect rectification and trials, she departed Sydney on 21 May for Jervis Bay where she conducted self-generated noise trials in conjunction with RAN Experimental Laboratory staff before continuing on for Melbourne the next day. The voyage was interrupted by inclement weather off Wilson’s Promontory that forced the patrol boat to seek shelter in Sealer’s Cove and Port Welshpool for a week. She eventually arrived safely at HMAS Cerberus on 30 May.

From Cerberus, Acute conducted a series of exercises in Victorian waters before assuming the role as a dedicated Royal Australian Naval Reserve (RANR) training vessel in October 1968. On 18 October, Lieutenant Commander Michael Coleman, RANR, assumed command and just ninety minutes later, departed Melbourne for Sydney. Acute arrived at HMAS Waterhen on 20 October and the next day, the Permanent Naval Force (PNF) members of the crew were relieved by their RANR counterparts who had travelled from Western Australia to join their new training ship.

Following a two-week work up programme, Acute departed Sydney on 4 November and arrived in Adelaide three days later. She departed Adelaide in company with HMAS Sydney (III) on 9 November and proceeded to cross the Great Australian Bight in atrocious weather. Sydney’s captain, Captain Domara Clarke, MVO, DSC, RAN, later reported that it was the worst crossing of the Bight he had ever experienced while Lieutenant Commander Coleman, a merchant navy officer in civilian life, reported that it was the worst weather he had ever encountered at sea. Coleman and his crew were later commended by both the Naval Officer in Charge, West Australia Area, and the Naval Board for their seamanship during the crossing. Acute arrived safely in Albany on 12 November before continuing on to her new home port of Fremantle where she continued her role as a RANR training vessel based firstly at HMAS Leeuwin and later at HMAS Stirling.

HMAS Acute on a rare visit to Sydney circa 1968
HMAS Acute on a rare visit to Sydney, circa 1968.

Acute served in that capacity for the next ten years providing valuable training to rotating RANR crews for two weeks at a time along the Australian west coast. This was in addition to regular weekend training and ‘day-runs’. Her training cruises took her all along the Western Australian coast, from Esperance to Broome. Part of her training responsibilities included hydrographic surveys off the Western Australian coastline including Wedge Island in August 1969, Woodman’s Point in October 1969, the approaches to Bunbury Harbour and Cape Naturaliste with HMAS Diamantina in February and March 1972, and again in March and April 1973, Lancelin in May 1976 with HMAS Moresby, and the Geelvink Channel in September and October 1978 again with Moresby.

Acute’s training cruise of May 1973, under the command of Lieutenant Commander Redmond 'Pat' Rodriguez, RANR, became more operationally focussed. On the evening of 2 May, while anchored off Point Murat, Acute received orders instructing her to proceed to Dampier to embark an officer of the Department of Primary Industries before proceeding to the Monte Bello Island group to investigate a possible incursion of illegal foreign fishing vessels, reported by the merchant vessel, SS Wamburi. Unfortunately a radar defect just minutes before getting underway made the ensuing operation all the more difficult.

Acute arrived in the area the following day establishing a search pattern and locating two Taiwanese registered vessels shortly before sunset. Boarding parties were sent across to the two vessels which were subsequently seized and sailed to Exmouth. Meanwhile Acute continued to patrol the area. Two more vessels were boarded later that evening but with the unserviceable radar making it difficult to establish their definite position, the two vessels were released with a warning. In any case, with five of the twenty one members of the small patrol boat crew already detached aboard the previously apprehended vessels, Lieutenant Commander Rodriguez doubted Acute’s ability to escort this second duo back to the mainland.

Acute rendezvoused with the previously apprehended vessels the following day and escorted them from Exmouth to Fremantle, a distance of around 1,000 nautical miles from the point of arrest. They arrived at Fremantle on 13 May, having steamed through a force six gale en route. The Naval Officer Commanding West Australia Area, Commodore Peter Doyle, OBE, RAN, later wrote “The conduct of the entire cruise, culminating in the successful arrest of two Taiwanese fishing vessels in the Declared Fishing Zone and their escort to Fremantle reflects the greatest credit on the captain of HMAS Acute and his company. It was a most praiseworthy combination of firmness and tact which enabled good relations to be maintained with the masters and crews of the captured vessels from the moment of arrest to eventual arrival in Fremantle.”

HMAS Acute was one of 20 Attack class patrol boats built for patrol duties in Australian and Papua New Guinea waters
HMAS Acute was one of 20 Attack Class patrol boats built for patrol duties in Australian and Papua New Guinea waters.

Fishery surveillance patrols became a regular feature for Acute manned by both reserve and permanent navy crews. A permanent navy crew was embarked in June 1976 to escort two more Taiwanese fishing vessels, arrested by HMAS Adroit for illegal fishing, from Exmouth to Fremantle, a task that was repeated by reserve crews that July. In June the following year, a reserve crew under the command of Lieutenant Commander Otto Pelczar, RANR, boarded nine vessels during what was meant to be a ten day training cruise. None of the vessels were arrested, but all were reminded of the relevant fisheries laws.

In August 1977, Acute visited the Monte Bello Islands to support radio activity surveys, transporting a small team of radiographers to the islands and providing the necessary logistic support. She repeated this task in July 1981.

In October 1978, Acute’s time as a dedicated RANR training vessel came to an end when she was again manned by a permanent navy crew. Henceforth, Acute participated in a regular programme of patrols, exercises and maintenance, though she was still occasionally made available for RANR training. The change of tempo also took Acute out of Western Australian waters for the first time since arriving there, when she visited Darwin in June 1979, a port she would visit regularly until her decommissioning.

She was the official guest at the Geraldton Sunshine Festival in September 1979 and that November embarked former Prime Minister, Sir John Gorton, GCMG, to start the Geraldton to Fremantle Yacht Race.

Acute sheltered from the fury of Cyclone Dean in Port Hedland Harbour when it struck on 1 February 1980 and was fortunate to suffer only minor damage in winds that reached 108 knots. Damage ashore was estimated to cause around $20 million damage and two sailors from a Taiwanese fishing vessel were lost west of Broome.

In March 1980 Acute underwent a major refit at HMAS Stirling and was back at sea in October undergoing inspections and trials. However, ongoing engine defects forced her to return to the Stirling slipway in March 1981.

HMAS Acute served as KRI Silea in the Indonesian Navy after decommissioning from the RAN
HMAS Acute served as KRI Silea in the Indonesian Navy after decommissioning from the RAN.

Acute participated in a Squadron Exercise off Darwin in May 1981 in company with her sister ships, HMA Ships Adroit, Ardent and Aware, and later participated in Exercise BEACON SOUTH 81 in August. She slipped for an intermediate docking in February 1982 and returned to the water on 10 March. She participated in Exercise BEACON SOUTH 82 just a week later and followed that up with exercises supporting the Special Air Service. She returned to Darwin for a Squadron Exercise in June.

On 24 July 1982, Acute embarked a small medical team and went to the assistance of the American submarine, USS Indianapolis, 240 nautical miles west of Perth. One of Indianapolis’ crew was suffering from a leg infection. The sea state was considered too rough to transfer the sailor to Acute so the medical team transferred to Indianapolis and Acute returned to Stirling leaving the medical team aboard the submarine. Indianapolis arrived at Stirling on 26 July and the ill sailor was transferred to Fremantle hospital by Navy ambulance where he made a full recovery.

Acute maintained a normal programme of patrols, exercises and maintenance until the end of 1982 when she underwent a refit in preparation for her transfer the Indonesian Navy. On 6 May 1983, HMAS Acute decommissioned in Darwin and transferred to the Indonesian Navy as part of the Defence Cooperation Programme, the fourth ex-RAN Attack Class patrol boat to be transferred to the Indonesian Navy. She was renamed KRI Silea.