Fay's Bay is a small, lesser-known bay tucked between Longreach Bay and Geordie Bay on Rottnest's north coast. The Rottnest Island Authority lists it among its six best snorkel spots, describing seagrass meadows within a shallow limestone reef with caves and channels, calm water and colourful schools of fish - a good choice for beginners - and notes its quiet, uncrowded character. The Authority's warm-water guide groups it with Geordie Bay as a spot with limestone caves, larger fish, stingrays and gloomy octopus.

The combination of seagrass and eroded limestone in shallow water gives a lot of variety for a small bay. Snorkellers can drift over the meadows looking for juvenile fish and pipefish, then follow channels through the reef where wrasse, bream and octopus shelter. Western rock lobster sometimes sit under ledges close to shore.

It suits families and beginner snorkellers who want a quieter alternative to The Basin, and scuba divers looking for a relaxed shallow dive. Because it is close to the settlement and less busy than its neighbours, it is a good early-morning or late-afternoon option.

The north-coast road passes right by, so the bay is easy to combine with Longreach and Geordie bays on a single ride.

Rottnest's north-coast bays are the island's summer snorkelling grounds because they sit in the lee of the prevailing south-westerly sea breeze. The Rottnest Island Reserve bans spearguns and handspears across all island waters, so fish throughout the bays are relatively approachable, and the Island Explorer bus and flat cycling road link them all. The general rule is simple: in a southerly, snorkel the north side.

About 2 km from the settlement - an 8-minute ride or 30-minute walk west along the north-coast road, or Island Explorer bus Stop 19. Walk down to the beach from the road and enter from the sand. Snorkel gear can be hired in the settlement; scuba divers must bring filled cylinders from Perth on the ferry, as there are no fills on the island.

SeaLink lists south-east, south and south-west winds as suitable; the bay faces north and is rough in northerly winds. Calm mornings are best. General pattern at Rottnest: summer brings calm morning easterlies followed by a strong south-westerly sea breeze from late morning, so dive early; winter brings north-westerly fronts and large swell, with clear, calm spells between them.

Check the Bureau of Meteorology coastal forecast for swell height and period before committing.

Enter from the beach, cross the seagrass to the limestone reef and follow its caves and channels, then return along the shore. Snorkellers should stay within easy reach of the exit point and swim with a buddy; scuba divers at these depths need no safety stop but should ascend slowly and surface near the float.

No operator needed - self-guided snorkel/shore dive. Snorkel gear hire from Pedal & Flipper and other outlets in the Thomson Bay settlement; guided snorkel tours (Rottnest Snorkel) run from Thomson Bay. Scuba divers bring cylinders from Perth - no fills on the island.