Greta Beach is a secluded east-coast beach reached by a walk of about 300 m from the car park and a steep staircase down the cliff. The Tourism Association describes a dreamy ocean pool inside the reef, with turtle nesting all year and red crab spawning during the migration; Parks Australia lists it as one of the easiest places to watch the spawning. It is also a collection point in the island's fight against ocean plastic, which washes up on the east-coast beaches from South-East Asia.

For snorkellers, the sheltered pool behind the reef offers shallow, clear water with coral and small reef fish – damsels, wrasse, surgeonfish, butterflyfish and parrotfish – and the chance of turtles, which nest on the beach and feed on the reef. It is best on calm days, as the east coast bears the brunt of the south-east trade winds for much of the year.

Greta is not a dive site on either operator's list, and the steep access rules out carrying scuba gear; it is included as a named coastal site that visiting divers and snorkellers often seek out. The open reef beyond the pool is exposed to surf and currents.

The beach's greatest spectacle is the red crab spawning. Between October and January, after the first wet-season rains, millions of red crabs migrate from the forest to the coast, and females release their eggs into the sea before dawn on the receding high tide during the last quarter of the moon. The larvae that hatch are a feast for fish, mantas and whale sharks. Suits snorkellers, wildlife watchers and photographers.

Fly from Perth (about 4 hours, two to three flights a week, some via Cocos Islands) and hire a car – there is no public transport. Drive from The Settlement up to the plateau via Murray Road/Lam Lok Loh, then out along the east-side roads (sealed to the airport and resort area; some beach roads are 4WD only – check the Parks Australia access report). Greta Beach is on the east coast south of the airport.

From the car park, walk about 300 m and then descend a steep staircase to the beach. The walk and stairs make carrying scuba gear impractical – it is a snorkel and swim site. Take water and reef shoes.

On the east coast, which takes the full force of the south-east trade winds from roughly April/May to November, when 15–25 knot winds and wind swell usually make it rough and undiveable by boat. It becomes the fallback coast in the wet season (December–March): when the north-west monsoon swell closes the north coast, the east side is often sheltered and calm. Dive it on light-wind days or during the monsoon.

Beyond the fringing reef currents can be strong and the reef edge is washed by surge whenever there is any easterly swell. Visibility is typically 20–30 m and drops after rain and during red crab spawning (Oct–Jan), when Ethel and Greta Beaches are spawning sites.

Snorkel inside the ocean pool at mid to high tide in calm conditions, staying well inside the reef edge. Avoid the surf zone and the open reef beyond.

No dive operator – self-guided snorkelling and swimming. Parks Australia runs beach clean-ups and turtle monitoring here.