The survey ship conducted multiple unsuccessful searches for "Sydney" and "Kormoran" between 1974 and 1991, when the ship was based in Fremantle. Another search was conducted by in July 1997. However, all RAN surveys were restricted to the continental shelf, as the navy did not possess the technology to effectively search the seabed off the shelf. The searches were not exhaustive, and were primarily a response to civilian claims that the wreck site was at a certain location, with the survey ship sent to prove or disprove the claim. Other searches were conducted by aircraft of the Royal Australian Air Force carrying magnetometers; again, these were only in response to claims of possible locations.