The Zeewijk was a VOC ship that struck Half Moon Reef in the Pelsaert Group on 9 June 1727 with 208 people aboard. The ship stayed wedged on the reef and did not break up immediately, allowing the crew to transfer goods, including treasure chests, to nearby Gun Island. Eleven men sailed for Batavia in a longboat on 10 July and were never seen again. The remaining survivors built a vessel from the wreckage – the Sloepie, the first European boat built in Australia – and 82 reached Batavia on 30 April 1728. During the ordeal two crew members were convicted of sodomy and marooned on separate islands.

Relics were found by HMS Beagle's crew in 1840, guano miners recovered material in the 1880s-90s, and Hugh Edwards led the rediscovery of the main wreck site in March 1968, followed by WA Museum surveys. Marine Life Network lists the site in 5-8 m with VOC cannon and coins, an interesting historical dive.

The outer reef location makes it one of the more difficult Abrolhos sites to reach, but it pairs with Half Moon Reef's seaward fish life and the Pelsaert walls for a southern-group itinerary. Everything is protected under historic shipwreck legislation. Material from the Zeewijk, including cannon and coins, is displayed at the WA Museum in Geraldton and Fremantle, which is worth visiting before the trip for context. Liveaboard itineraries typically reserve the southern group for the calmest day of the trip, and the Zeewijk visit depends entirely on the swell forecast.

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 Zeewijk site is on Half Moon Reef, the outer reef of the Pelsaert Group (the southern group), about 70 km (3.5-4 hours) from Geraldton.

Liveaboards visit only in calm conditions, anchoring in the lagoon and approaching by tender. Consult the WA Museum regarding site access.

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. Half Moon Reef is the exposed outer barrier of the Pelsaert Group and takes the full south-westerly swell; the site can only be dived in near-flat conditions.

Approach by tender in flat conditions, dive the reef at 5-8 m where cannons and debris lie, stay clear of the breaking reef edge.

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.