Elizabeth Reef is one of the two southernmost coral reefs in the world and part of the Lord Howe Marine Park's northernmost National Park Zone. Wikipedia gives its size as 10.5 km by 6.1 km, with Elizabeth Island, a sand cay about 50 m across and a metre above sea level, and a lagoon of deep water inside the reef. Salvage records mention a north-east entrance leading to a large harbour with anchorage in about 15 fathoms.

The reef is best known to scientists and the few divers who reach it for its fish. A 2003 survey recorded 111 coral species and 181 fish species, and the total fish list stands at 311. It holds high numbers of the threatened black cod and very high numbers of Galapagos sharks, which may indicate a nursery. Green turtles are also present. Parks Australia describes diving and snorkelling here as a once-in-a-lifetime marine life experience.

The reef is also a ships' graveyard. At least 12 major wrecks are documented, including the Britannia (1806), Tyrian (1851), Packet (1857), Colonist (1870), Alma (1883) and Askøy (1911), and the combined Elizabeth–Middleton list runs to 26 named wrecks and a dozen unidentified sites. Most remains are broken and scattered on the reef flat and are protected as historic shipwrecks.

There are no facilities, and access requires an ocean-going vessel and a long passage in settled weather. Diving and snorkelling are permitted without a permit, but recreational fishing requires a Parks Australia permit. The reefs are listed as a Ramsar wetland. It is a destination for expedition divers with sea time and self-sufficiency; depths vary widely and are not published, so plan conservatively.

Elizabeth and Middleton Reefs are remote, uninhabited coral reefs in the Tasman Sea, about 150 km (Elizabeth) and 230 km (Middleton) north of Lord Howe Island and 555–600 km off the NSW coast. There are no facilities, moorings or regular dive trips. Access is by private ocean-going yacht, research vessel or occasional expedition charter departing Lord Howe or the NSW coast, typically a one- to two-day passage each way.

Anchoring is possible in the lagoon in suitable weather; Elizabeth has a north-east entrance historically recorded with about 7 fathoms over the bar at low tide.

The reefs are fully exposed to the open Tasman Sea. Passage and diving require a settled window of light winds and small swell; any sizeable south-east trade wind swell or a southerly change makes the outer reef undiveable and the lagoon anchorage uncomfortable. Late summer and autumn (February–May) are the likeliest months for calm windows; winter brings fronts and big seas.

Tropical cyclones and ex-tropical lows can track through between December and April. Visibility on the outer reef is often 30 m or more.

Plan dives from an expedition vessel anchored in the lagoon: sheltered lagoon bommies first, then the outer reef slope on calm days, drifting along the edge with the tender following. Keep groups tight because of the Galapagos shark numbers.

No regular operator – private ocean-going yachts, research vessels and occasional expedition charters only.