Dirk Hartog Island is Western Australia's largest island (about 80 km long), named for the Dutch captain who landed there in 1616 – the first recorded European landing on the west coast – leaving a pewter plate at Cape Inscription. It is now a national park within the Shark Bay World Heritage Area, the subject of an ambitious 'Return to 1616' project reintroducing native mammals.

The Shark Bay tourism guide lists Surf Point, a sanctuary zone at the southern end of the island, as having good coral cover and abundant fish in shallow water. The mix of Indian Ocean and bay water here supports corals, tropical and subtropical reef fish, and large visitors from the passage.

Access requires the island barge from Steep Point or transfers from Denham, and the island's 4WD tracks require permits. Divers must be self-sufficient; there are no dive services. The reward is some of the most remote and pristine snorkelling in Shark Bay.

Reach Dirk Hartog Island by the vehicle barge from Blackies Beach (6 km south-east of Steep Point) across South Passage to Cape Ransonnet, or by boat or air from Denham (Dirk Hartog Island Eco Lodge transfers). Surf Point is at the island's southern end near the barge landing; 4WD tracks on the island require a permit and bookings (DBCA/island operator).

Shark Bay is dominated by strong southerly winds, which blow most days from about October to March and often exceed 20 knots by late morning; the calmest conditions are in April-June and on early mornings. The inner bay is shallow and well protected from ocean swell, but the western shores of Dirk Hartog Island and Steep Point face the full Indian Ocean. Water is 17-19°C in winter and 23-26°C in summer.

Surf Point sits beside South Passage, where tidal currents are strong; snorkel near slack water in calm weather.

Snorkel the sanctuary zone near slack water, staying in the shallows over the coral and keeping out of the passage current.

No dive operator; independent visitors via the island barge or Eco Lodge.