Magistrates Rock is one of the Recherche Archipelago's most exposed dive sites – a rock that rises from about 30 m to a highest point of 14 m, taking the full force of the Southern Ocean swell. Marine Life Network notes that it is usually hard to dive, but that on calm days the waters are clear and the rock is undercut into caverns.

Constant swell has carved the rock into overhangs and small caves and keeps it scoured, so the growth is dominated by hardy sponges, encrusting coralline algae and kelp, with fish concentrated in the lee and in the caverns. Expect blue groper, queen snapper, harlequin fish, boarfish and schools of sweep, and potentially pelagic visitors such as kingfish and samson fish.

This is an opportunistic site for experienced divers on an Esperance trip that happens to coincide with a rare flat spell. There is little published detail and no public GPS mark.

Esperance is about 720 km (8 hours) south-east of Perth via the Albany or Great Eastern and Coolgardie-Esperance Highways, with daily flights from Perth. Dive boats and private boats launch from the Bandy Creek Boat Harbour (5 km east of town, with ramps, parking and toilets) or operate from the town waterfront on The Esplanade. Air, nitrox and hire gear are available from Esperance Diving & Fishing on The Esplanade.

Magistrates Rock is an exposed offshore site; operators hold the mark and visit only in near-flat conditions. Allow about an hour by boat from Esperance.

The Recherche Archipelago lies open to the Southern Ocean, and the islands shelter each other only partly. Boat diving needs swell under about 2 m and winds under 15-20 knots; the prevailing south-westerly swell and winter cold fronts cancel many trips from May to September. Summer brings reliable morning calms but strong easterly sea breezes most afternoons.

Marine Life Network describes Magistrates Rock as usually hard to dive because it is hammered by swell; it is only feasible in rare flat, calm conditions, when the water is very clear.

Descend to the top of the rock at 14 m, circle it at 20-25 m looking into the undercut caverns, then ascend to the top for the safety stop and pickup by live boat.

Esperance Diving & Fishing (72 The Esplanade, Esperance; operating since 1983) – boat dives in the Recherche Archipelago on demand/weather permitting, minimum numbers apply for long trips – rarely, in exceptional conditions.