Long Island is one of the western islands of the Recherche Archipelago, and one of the more varied reef dives accessible from Esperance. Marine Life Network describes large rock formations with caverns and swim-throughs, and reef ridges separated by sand gutters, in 20-30 m, with western blue groper, queen snapper and harlequin fish (harlequin cod) as signature species.

The granite has been sculpted into overhangs and caverns lined with sponges, ascidians and gorgonians, and the ridges and gutters give the dive a structured, easy-to-navigate layout. The blue groper here are large and curious, queen snapper school in the gutters, and harlequin fish sit in the caves. In the sand gutters look for rays and flathead.

The island also shelters the Lapwing, an intact small fishing-boat wreck in 32 m, so Long Island makes a natural two-dive day: the wreck first, then a shallower reef dive. The site suits Advanced Open Water divers; swim-throughs should be avoided if there is surge.

The Recherche Archipelago – more than 100 granite islands and 1,500 islets stretching 230 km along the coast – is one of the least-dived temperate island groups in Australia. With the local operator the only regular dive boat, divers who make the trip often have sites to themselves. Surveys record more than 260 fish species and 450 sponge types across the archipelago, and the sponge diversity is obvious on the Long Island walls, where every overhang holds a different colour and form. Plan Long Island as part of a multi-day Esperance stay to allow for weather.

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.

Long Island lies in the western part of the archipelago; allow 30-45 minutes by boat. Operators anchor in sand in the lee, choosing the side according to swell. Often combined with the Lapwing wreck.

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.

Dive the lee of Long Island in south-westerly swell; exposed sides need near-flat conditions. Swim-throughs and caverns surge badly in any swell over about 1 m.

Anchor in the lee, descend to 20-25 m and follow the reef ridges and sand gutters, detouring through swim-throughs only in calm conditions, then return shallower along the rock formations.

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.