Assail was initially based in Sydney before relocating to Darwin in 1969. From there she conducted continuous patrol work and was involved in a number of arrests of foreign fishing vessels that had been caught illegally fishing in Australian waters.
She was also involved in escorting several boatloads of refugees to Darwin for processing and provided survey support to HMAS Moresby (II). Occasionally the patrol work was punctuated by visits to Indonesia and Papua New Guinea.
In December 1974 Assail sustained damage during Cyclone Tracy when she broke free of her moorings that necessitated her having to ride out the violence of the cyclone under her own power within Darwin harbour. Following this ordeal her Commanding Officer, LEUT Chris Cleveland, RAN reported that the vessel had rolled up to 80 degrees and that on several occasions her navigation lights had been in the water.
In 1983 Assail home ported to Western Australia where she remained until 1985 before returning to Sydney. During her final year of commission in the RAN, Assail conducted Bass Strait oil rig support patrols from Sydney before decommissioning in October 1985.
Assail was then transferred to the Indonesian Navy and re-named KRI Sigurot. She is still listed as being active in the 2008 edition of Janes Fighting Ships.