Wreck Reefs take their name from one of the most famous shipwrecks in Australian history. On 17 August 1803 HMS Porpoise, carrying Matthew Flinders back to England after his circumnavigation of Australia, and the merchant ship Cato struck the uncharted reef at night. Wikipedia and Parks Australia record that most of the crews survived on a sandbank; Flinders sailed an open boat to Sydney to organise a rescue, and the survivors were eventually taken off by the Rolla and the schooner Cumberland. Parks Australia records three deaths. The Coral Sea shipwreck register also lists the barque Mahaica (1854), the whalers Jane and Lion (1856) and the schooner Lone Star (1871) as lost here.

The wreck sites of the Porpoise and Cato were found in 1965 by Ben Cropp and Jiri Hrbac after extensive research and, famously, only fifteen minutes of actual diving. Artefacts and structural remains lie among the coral; after more than two centuries, little recognisable structure is likely to remain beyond anchors, cannon, ballast and fittings. Parks Australia notes that the sites are now dive locations. The Wreck Reefs zoning map marks a wreck at the eastern end of the complex.

The reef itself impressed Reef Life Survey divers, who found outstanding visibility, deep blue water, and whitetip and grey reef sharks, black snapper, humpnose unicornfish, Maori wrasse, parrotfish, groupers, tuna, rainbow runner, marlin, Queensland groper and sea snakes, though virtually no sponges or gorgonians.

The sites are protected underwater cultural heritage; nothing may be touched or removed. It suits self-sufficient expedition divers with an interest in maritime history.

There is no scheduled dive operator. Access is by private expedition charter, research voyage or cruising yacht with Coral Sea experience, self-sufficient for several days and carrying compressor, oxygen and satellite communications. Wreck Reefs lie about 450 km east-north-east of Gladstone, two days or more each way; Reef Life Survey reached them overnight from Cato Reef, about 100–120 km to the south.

Anchor in the lee of the cays in calm weather. Commercial tours need Parks Australia authorisation, and some islands are closed to landing.

These are remote oceanic reefs with no shelter from the south-east trades beyond their own reef rims, which blow 15–25 knots for much of April to October and make the multi-day open-ocean passage rough. Expeditions target calm windows, most often September to December; the lagoon anchorages give protection in moderate trades but the outer walls are dived only in light winds. December to April is cyclone season and trips are rarely scheduled then.

Currents on the walls and through passes can be strong; visibility is usually 30 m or more.

Dive the reef around the historic wreck sites in calm weather with a guide who knows their location, looking but not touching; then explore the surrounding reef slope. Keep well within no-decompression limits given the remoteness.

Historic artefacts only – no structure to penetrate.

No regular operator – occasional private expedition charters, research voyages and cruising yachts only; any commercial tour requires Parks Australia authorisation.