Thevenard is Ceduna's port, a working harbour that exports gypsum, grain and salt, and the area's jetties sit on the sheltered waters of Murat Bay at the western end of Eyre Peninsula, on the edge of the Nullarbor. Recreational jetties on Murat Bay stand over sand and seagrass in shallow water, with algae, sponges and ascidians on the piles and schools of garfish, Australian salmon, snook and tommy ruff around them, plus blue swimmer crabs and squid. The Marine Life Society describes the nearby Ceduna old jetty as an easy shallow dive day or night with some debris on the bottom (see separate entry).

Thevenard's most significant dive is offshore: the wreck of the Eleni K, a Liberty ship lying between Goat Island and St Peter Island, which the Society describes as one of the best shipwreck dives in South Australia (see separate entry). Divers visiting Ceduna should plan around that wreck, using the jetties as easy shore dives. Data confidence is low; confirm access with locals before diving.

Ceduna is about 780 km (8.5 hours) from Adelaide via Port Augusta and the Eyre Highway, with flights available. Thevenard is 4 km south-west of Ceduna town centre. Use the public/recreational jetty area rather than the operational shipping wharf, which handles gypsum and grain and is closed to the public.

Check locally for current access before diving.

The west coast of Eyre Peninsula faces the Great Australian Bight and receives almost constant south-westerly Southern Ocean swell; open-coast sites need swell under about 1.5 m and are only diveable a handful of days a month, usually after several days of northerly or easterly winds, which blow offshore. The large sheltered bays (Coffin Bay, Waterloo Bay, Venus Bay, Baird Bay, Streaky Bay, Denial Bay) are protected from swell and can be dived in most conditions except strong onshore winds. Summer brings strong afternoon south-easterly sea breezes; winter brings cold fronts with big swell but also calm, clear spells.

Water is cool: about 14-15°C in winter and 17-21°C in summer. Murat Bay is sheltered by islands and peninsulas; wind is the main limitation.

Swim along the piles over sand and seagrass, look for small life, and return; keep well away from the commercial wharf.

No operator; occasional visiting divers.