Saumarez Reefs lie in the southern Coral Sea about 330 km north-east of Gladstone and 85 km east of the Swain Reefs, the outer edge of the southern Great Barrier Reef. Wikipedia describes a crescent-shaped reef system about 27 by 14 km, open to the north-west, with three main reefs and many smaller ones, and two sand cays, North East Cay, which carries a light, and South West Cay.

Diving here is by private vessel only. The crew of the cruising yacht Anui, who visited in 2024, describe a thin rim of reef that nevertheless gives adequate protection, anchoring in about 10 m over sand near the wreck of the Francis Preston Blair and later at a shallower anchorage to the south-west. They found coral like undulating meadows as far as the eye could see, bleached but still alive, with colourful reef fish, blue tangs, surgeonfish, giant clams, sea turtles and olive sea snakes. Snorkelling was better near the reef edge by the wreck than at the south-west anchorage. A Reef Life Survey expedition in the same region had to abandon plans to dive Saumarez and the Swains when winds rose above 30 knots with 3 m swells, a reminder of how exposed the area is.

The reef's main historical feature is the Liberty ship Francis Preston Blair, wrecked on the eastern edge in July 1945, which has its own row in this database.

Saumarez suits self-sufficient cruising divers and snorkellers. It is zoned Habitat Protection Zone (Reefs), with a Special Purpose (Trawl) zone around it, so fishing is permitted and fishing boats may be encountered.

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. From Gladstone the passage is about 330 km; cruising yachts report about 210 nautical miles from Hervey Bay.

Anchorage is inside the crescent over sand in about 10 m, including near the wreck of the Francis Preston Blair; a second, shallower anchorage lies further south-west. 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.

Snorkel or dive the reef edge near the wreck anchorage and the coral meadows inside the crescent, keeping to the lagoon in trade-wind weather. Outer-reef dives only in calm conditions with tender cover.

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