on South Australia’s mainland on the night 7/8 November 1940. To ensure an accurate lay, Passat’s chart indicated where the mines were to be laid. Red lines were drawn on the chart between Kangaroo Island to the mainland across Backstairs Passage. On top of these lines were little blue crosses signifying the minefield to be laid in the southern shipping lane to and from Adelaide. Passat also used the lighthouses at Cape Willoughby and Cape Jervis both of which were fully operational as accurate navigational aids. The narrow ‘Backstairs Passage’ made HMAS SWAN post World War II with Midshipman’s it an ideal ‘choke’ point. ’Gunroom’ at the stern Pinguin laid her field at the western end beIt was passing tween Cape Catastrophe and West Cape (at the foot and thought to be a naval vessel. of Yorke Peninsula) through which shipping passed through the narrowest part of Backstairs Passage to Port Pirie, Whyalla and Port Augusta. The plan where the mines were to be laid. The naval vessel steered towards Passat, which was to meet up with Passat 700 miles west of Perth continued on with her mission. On board Passat a on 15 November. Anchored bow wave could be seen rising as the naval ship inWhilst laying mines, Passat and a naval vessel be- creased speed. Oberleutenant Warning determined it lieved to be either HMAS Warrego or HMAS Swan was impossible to turn back now. met in Backstairs Passage. “Action stations” were ordered. Warning beThe Report of Proceedings and War Diaries for lieved the cover of Passat had been revealed and exNovember 1940 for both RAN ships had them either pected the naval vessel carrying out destroyer type in or in close proximity to Backstairs Passage on 7/8 manoeuvres to recognise Passat’s true identity as a November 1940. Another 6 naval auxiliary vessels German Minelayer. attached to HMAS Torrens (Naval HQ SA) were paAs the men moved quickly to their action statrolling SA waters at the time. After patrolling the tions, the ‘German Naval Battle Ensign’ was made Gulf of St. Vincent, Investigator Strait and Backstairs ready to be hoisted at a moment’s notice. The naval Passage, HMAS Swan anchored at Eastern Cove, vessel was right ahead of the Passat now, crossing Kangaroo Island late on 7 November. At 0140 on the her bows. 8 November, HMAS Swan weighed anchor and proceeded en-route to Melbourne via Backstairs Passage in company with HMAS Warrego who had earlier anchored a short distance away in Nepean Bay. It was more than probable, Passat met one of these RAN ships. It was soon after mine laying operations commenced that evening, a vessel was reported approaching by watchkeepers in Passat. The outline of Backstairs Passage, Nepean Bay and Eastern Cove the area PASSAT, the oncoming vessel HMAS WARREGO and HMAS SWAN were on night 7/8 November could plainly be seen
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