 Like the "Oberon" class, the "Collins"-class submarines have conducted surveillance patrols.In 1999, it was reported that "Waller" and a second boat operated in support of the International Force for East Timor (INTERFET) providing escorts for transport ships, monitoring Indonesian communications, inserting special forces and had been collecting intelligence on East Timor for months.A submarine, possibly "Waller", reportedly inserted Navy clearance divers into the Oecussi Enclave to conduct a covert beach reconnaissance ahead of an amphibious landing on 22 October 1999.