The Bronzewing was a small steel tug, 17.7 m long, built in 1930 for the Royal Australian Navy. After a long working life she was acquired by the Port Lincoln Game Fishing Club and scuttled in Boston Bay in 1990 as an artificial reef. The Marine Life Society places her near Bass Shoal, about a nautical mile off Port Lincoln, in 5-7 m.

Shallow scuttled vessels in sheltered bays become fish magnets quickly, and after more than three decades the tug is encrusted with algae, sponges and ascidians and attracts leatherjackets, old wives, magpie perch, tommy ruff, King George whiting and snapper, with crabs and octopus in the structure. Cuttlefish and squid are common in the bay. The Society notes the site can suffer from poor visibility, as Boston Bay is shallow and fine sediment is easily stirred.

On a calm day with good water, it is a relaxed, easy wreck dive close to town, suitable for Open Water divers and useful for wreck-skills practice. Because no public coordinates are available, divers need local marks. It combines with the town jetty or Kirton Point as a Port Lincoln diving day when weather keeps boats inshore.

Recreational fishers target the wreck, so expect anchored boats and lines, particularly at weekends, and keep a cutting tool handy. Visibility is usually best after a run of calm weather and on the top of the tide, when clearer water pushes into the bay from Spencer Gulf. The shallow depth means long bottom times on a single cylinder, and it is a good place to practise wreck navigation and buoyancy before tackling deeper wrecks elsewhere in the state.

Port Lincoln is about 650 km (7 hours) by road from Adelaide via Port Augusta and the Lincoln Highway, or a 45-50 minute flight (Rex/QantasLink). Launch at Lincoln Cove Marina or the town ramps and run into Boston Bay; the Marine Life Society places the tug near Bass Shoal, about 1 nautical mile off Port Lincoln and 6 nautical miles west of No. 4 beacon. Exact marks are available from the Port Lincoln Game Fishing Club and local dive shops.

Boston Bay and the waters around Port Lincoln are sheltered from Southern Ocean swell by Boston Island and the Lincoln National Park coast, so the town jetties can be dived in most weather; strong south-easterly and easterly winds are what chop them up. The islands of Thorny Passage and the lower Eyre coast are progressively more exposed to south-westerly swell and strong tidal streams, and need swell under about 1.5-2 m and light winds. Winter (May-August) brings frequent cold fronts with big south-westerly swell but also calm, clear spells; summer has more reliable weather but regular afternoon south-easterly sea breezes.

Water is cooler than the gulfs, around 13-15°C in winter and 17-20°C in summer. The Marine Life Society notes the Bronzewing can suffer from poor visibility.

Descend the shot to the hull, circle the tug at 5-7 m, look into open areas from outside, and return to the shot.

No regular operator; locals and dive shop customers with boats; popular with anglers.