The Hadda was a 334-ton, three-masted timber barque that sailed from the Lacepede Islands north of Broome on 12 April 1877 with a cargo of guano for Fremantle. Her captain intended to pass east of the Abrolhos through the Geelvink Channel, but uncharted currents pushed the ship west, and on 30 April she struck the northern shelf of a reef only a few hundred metres from Beacon Island, bow first and hard aground. The crew abandoned her and sailed the ship's boat to Geraldton; a court of inquiry cleared the captain. The ship was probably partly salvaged, as anchors and deck machinery are not evident.

Being timber, little of the hull survives, but divingwawrecks and Marine Life Network describe numerous iron knees that supported the decks, the keel, a few fittings and hull sheathing, scattered over about 40 x 20 m in 2-6 m. The real attraction is the setting: the site is in a sanctuary zone surrounded by abundant coral gardens – staghorn, plate and finger corals – with buffalo bream, baldchin groper, sergeant majors, wrasse and parrotfish.

The site is sheltered from all but northerly weather, making it one of the more reliable dives in the Wallabi Group and an easy snorkel for all levels. It is usually combined with the Batavia site on nearby Morning Reef and the Beacon Island trail. Because it is shallow and sheltered, the Hadda is often used as a snorkel stop between deeper dives, or as a night snorkel from a liveaboard anchored nearby, when crays and octopus emerge among the knees.

The Houtman Abrolhos lie 60-80 km west of Geraldton (about 420 km north of Perth). There is no public accommodation or camping on the islands, so divers visit on liveaboard trips departing Geraldton (a 3-5 hour crossing), on private vessels using the public moorings, or – for snorkelling only – on scenic-flight day tours that land on East Wallabi Island. The Hadda lies about 720 m east-north-east of Beacon Island in the Wallabi Group.

There is a convenient sand patch nearby for anchoring without damaging the coral. Liveaboards and private boats visit as part of Wallabi Group itineraries.

The Abrolhos sit on the edge of the continental shelf in the path of the warm Leeuwin Current, which keeps water at 20-24°C and supports the world's southernmost major coral reefs. The islands are exposed to the south-west swell and to strong southerly winds that blow most afternoons from October to March; the crossing from Geraldton is often rough. Marine Life Network recommends March-May and September-November; late summer-autumn highs give the calmest seas.

Western rock lobster season (15 March-30 June) brings fishing camps and boat traffic. divingwawrecks describes the Hadda as well protected from most weather and exposed only to the north; diveable in swell up to about 1.5 m. Marine Life Network advises calm weather.

Anchor on the sand patch, snorkel or dive over the 40 x 20 m debris field following the line of iron knees and keel, then explore the surrounding coral gardens.

Liveaboard only for diving: Image Dive – 'Southern Image', the only dedicated dive boat at the Abrolhos (4 days/4 nights from Geraldton, max 8 divers, 3-4 dives a day); Eco Abrolhos Cruises – 5-day small-group cruises from Geraldton with snorkelling and diving; occasional Perth club charters. Batavia Coast Dive & Watersports (Geraldton) runs Abrolhos trips when boats are available.