1 ATF was redeployed on 12 May to obstruct the withdrawal of forces from the capital, with two battalions establishing a fire support base named FSB Coral, just east of Lai Khê in Bình Dương Province, in an area of operations known as AO Surfers.

Exploiting the disorganised defence to penetrate the Australian perimeter, the PAVN 141st Regiment temporarily captured a forward gun position during close-quarters fighting, before being repulsed by superior firepower that morning.

[2][3] Regardless, 1 ATF was also available for deployment elsewhere in the III Corps Tactical Zone and with the province coming progressively under control throughout 1967, the Australians would increasingly spend a significant period of time conducting operations further afield.

Prior to Tet, American commanders and politicians had talked confidently about winning the war, arguing that General William Westmoreland's strategy of attrition had reached the point where the PAVN/VC were losing soldiers and equipment faster than they could be replaced.

[6] Yet the scale of the offensive, and the surprise and violence with which it had been launched, had shocked the American public and contradicted such predictions of imminent victory; in its wake President Lyndon Johnson announced that he would no longer seek a second term in office.

A combined force of infantry from 3 RAR supported by armour then advanced on the foothills, before clearing the minefields and destroying an extensive base area which included a deep cave system that had first been used by the Việt Minh against the French in the 1950s.

[19] On 8 April, Westmoreland launched a series of large-scale sweeps involving over 70,000 South Vietnamese, American, Australian, New Zealand and Thai troops, code-named Operation Toan Thang I.

[23] VC activity in their traditional base areas in the Hat Dich north of Nui Thi Vai hills, had been increasing in February and March and 3 RAR subsequently commenced operations along the north-western border of Phước Tuy Province on 21 April.

Leaving its supporting artillery and one infantry company for protection, 3 RAR would then move west to establish blocking positions and patrol AO Manly in order to intercept PAVN/VC forces attempting to withdraw from the south and south-west.

[41] 1 ATF was not well practised in flying in and setting up a large fire support base, and a poorly co-ordinated, prolonged and dislocated operation caused considerable delay in getting on the ground, and the scattering of a number of units.

[46] Although the Australians made further efforts to co-ordinate their defences prior to last light, attempting to tie in their positions to achieve mutual support between the sub-units, these arrangements remained incomplete as night fell.

[49] The PAVN divisional commander had quickly dispatched reconnaissance elements to observe the fly-in of the Australians and their defensive preparations during the afternoon, and they soon reported the opportunity to attack the exposed gun positions of the 102nd Field Battery.

[51] Yet despite a number of minor clashes the PAVN successfully bypassed the Australian rifle companies, conducting a forced march under cover of darkness and rain to dig in within 250 metres (270 yd) of FSB Coral undetected.

The guns were then depressed to fire the shell at the ground approximately 40 to 50 metres (44 to 55 yd) in front of the emplacement, which caused the round to ricochet and explode in the air above the heads of the assaulting force, an expedient which proved very effective.

[62] While Radio Hanoi quickly announced a major PAVN victory there was little doubt that the Australians had convincingly repulsed the attack, even if they had come close to suffering a military catastrophe, with the task force headquarters itself nearly being destroyed.

[69] Hughes arrived at 08:00 and directed Bennett to redeploy his companies in all-round defence of FSB Coral, with 1 RAR consolidating their defensive arrangements with wire, sandbags, overhead protection and claymore mines, while tripod-mounted machine-guns were also emplaced to fire on fixed lines.

[75] The unsuccessful assault against FSB Coral on the night of 12/13 May had demonstrated that the PAVN would react violently to Australian attempts to control AO Surfers, and with 1 ATF deployed astride a key route to Saigon and threatening a number of PAVN/VC bases and staging areas located nearby, further heavy fighting was expected over the following days.

[75] During the afternoon, the patrol activity resulted in heavy fighting, and two separate actions fought within half an hour of each other by different platoons from 1 RAR led to two Australians being awarded the Distinguished Conduct Medal (DCM)—Lance Corporal David Griffiths and Private Richard Norden.

[77] The PAVN/VC appeared to be probing the Australians to gain information on their dispositions and these efforts continued the following day with the defenders observing two PAVN near the perimeter of FSB Coral, while patrols from 1 RAR later contacted a number of small groups and uncovered a recently used company-sized camp just 1,000 metres (1,100 yd) from the base.

[89] Under the command of Major Peter Badman, the slow-moving armoured column departed on 22 May, traversing the difficult terrain that included a number of old, rusting Bailey bridges, which threatened to collapse under the 50-tonne weight of the Centurions.

[88][92] Shelton was keen to avoid the mistakes that had been made during the earlier occupation of FSB Coral however, and he sent two companies forward on foot to occupy the new fire support base while the battalion tactical headquarters accompanied them in APCs.

[94] Dunstan subsequently directed the clearance of the bunker system that had been located the previous day, and a combined force of D Company, 1 RAR and 1 Troop C Squadron under the command of Major Tony Hammett was tasked with carrying out a reconnaissance-in-force.

[96] Departing at 06:00 on the morning of 26 May, at 12:27 the lead Australian infantry platoon was hit by small arms fire and RPGs 3,000 metres (3,300 yd) from Coral, after having paused to direct an air strike by Canberra bombers from No.

Further bunkers were exposed when the foliage was cut away by canister rounds and the infantry followed the tanks using rifles and grenades, while assault pioneers provided support with a flame-thrower as artillery and mortar fire engaged targets further away.

However, with aerial reconnaissance revealing that the bunker system was part of a much larger base area, and with the Australian force judged too small to deal with it, Bennett directed Hammett to retire by late afternoon.

[110] Many of the PAVN dead were teenagers of 16 or 17 years, evidence that the North Vietnamese had begun drafting 15-year-old boys into its combat units; as had happened after the earlier fighting, their bodies were collected by a bulldozer and buried in a mass grave.

[114] Three days later C Company returned to the area to recover the lost machine-gun only to find the position as they had left it; strewn with dead bodies and caved-in bunkers with the battlefield having been abandoned by the PAVN, who had also withdrawn following the Australian assault.

Over the next four years the tanks would provide invaluable close support, particularly during the clearance of bunker systems, proving to be powerful weapons in both offence and defence and were later credited with limiting casualties among the Australian infantry.

[137] The Australians then attempted to interdict VC supplies, with a small force of tanks and APCs supported B Company 3 RAR occupying the area along Route 15 to the west and north-west of Bà Rịa, the provincial capital, between 25 and 30 June during Operation Ulladulla.

[140] Continuing until 30 September, the renewed offensive lacked the scale of the previous attacks and again resulted in heavy communist casualties, failing to produce lasting military gains and contributing to an overall decline in PAVN/VC combat power in the south.