The Marine Life Network notes that some of the best dives on Groote Eylandt are 'with the dolphins at the wharf' at Alyangula. Alyangula was established in the late 1960s by the Groote Eylandt Mining Company (GEMCO) as the residence for its manganese mine workers, and its wharf area on Milner Bay is part of the island's working port.

Wharves in the Gulf of Carpentaria become artificial reefs: pylons encrusted with sponges, ascidians, oysters, hydroids and soft corals shelter a rich community of small invertebrates – nudibranchs, flatworms, shrimps and crabs – and schools of fish such as snapper, trevally, batfish and baitfish, with cod and groper in the shade. The distinctive attraction here is the dolphins that frequent the area, which divers and snorkellers have encountered at the wharf.

Because the Gulf has smaller tides and less river outflow than the western Top End, visibility at Alyangula is generally better than at Darwin's wharves, although ship movements and wind stir up the bottom.

Diving at any active port requires permission and strict avoidance of shipping, and this should be arranged locally before entering the water. Dolphin encounters must follow national guidelines: no feeding, touching or pursuing. Within those limits, the wharf is an easy, shallow site suited to all certified divers and to macro photographers, and is a convenient option when boat conditions are poor. A snorkel along the wharf edge at slack water can be as rewarding as a scuba dive when dolphins are present.

Groote Eylandt is about 630 km east of Darwin: fly to Groote Eylandt airport (about 1.5 hours from Darwin or 40 minutes from Nhulunbuy). A recreation permit from the Anindilyakwa Land Council is required before visiting, and commercial accommodation is limited – the Aboriginal-owned Dugong Beach Resort is the main option, as the mining company does not provide tourist accommodation. Boats launch at Alyangula on the island's west coast; sites are a short run from town.

Accessing dive gear on the island may be difficult – bring your own and arrange fills in advance.

Groote sits well inside the Gulf of Carpentaria, where tidal ranges are much smaller than at Darwin and there is less river outflow, so visibility and coral life are better in shallow water. From April to September the south-east trade wind blows strongly and the west-coast sites around Alyangula are in its lee, making them diveable on most mornings. The build-up (October–December) brings the calmest seas.

In the wet season (December–March) the monsoon can bring north-westerly winds onto the west coast, cyclones form in the Gulf, and box jellyfish are present; inshore visibility drops after heavy rain.

With port permission and no shipping operations, enter beside the wharf, descend to 6–10 m and move slowly along the pylons and bottom. Let dolphins approach on their own terms – do not chase or touch them. Ascend beside a pylon clear of any vessel movements.

No commercial dive operator on Groote Eylandt. Diving is done by residents (mostly mining-community members) with private boats; Dugong Beach Resort and Groote Eylandt Sports Fishing run fishing trips and may assist by arrangement. Visitors must bring or arrange their own dive gear and air.