Fish Hook Bay sits at the West End of Rottnest, close to Cape Vlamingh and the boardwalk lookout. SeaLink describes it as a pristine, untouched location with turquoise waters and an extensive reef system, tropical fish and other marine species, and excellent visibility. It lies within the West End Demersal Sanctuary Zone, which protects bottom-dwelling species such as western rock lobster and dhufish.

The bay's limestone reef is cut into ledges, gutters and small caves, and the clear water that reaches the West End gives some of the best visibility of any shore site on the island. Fish life is good because of the sanctuary and the distance from the crowds; expect wrasse, buffalo bream, herring cale, sweep and dusky morwong, and possibly seals from the nearby colony.

This is a snorkel for calm days and for people willing to cycle the length of the island. The West End is fully exposed to the south-west, and the swell can wrap into the bay with little warning, so check conditions from the lookout before entering. It suits confident snorkellers, and on a flat day it is one of the most scenic swims on Rottnest.

Bring water and food: there are no shops at the West End, and the ride back into the sea breeze can take an hour.

The West End is the most exposed part of Rottnest and the only part of the island where shore snorkelling is regularly limited by Southern Ocean swell rather than wind, so plan West End snorkels around the swell forecast. The Rottnest Island Reserve bans spearguns and handspears across all island waters.

Cycle to the West End (about 10-11 km from the settlement; allow 45-60 minutes) or take the Island Explorer bus to the Cape Vlamingh/West End stop. Walk from the Cape Vlamingh parking area down to the bay. The walk and ride make scuba impractical for most; this is mainly a snorkel.

Boats can visit on calm days (1.5 hours from Fremantle).

SeaLink lists north, north-east, east, south-east, west and north-west winds as suitable, and describes excellent visibility. The West End is exposed to Southern Ocean swell, so only snorkel on low-swell days; any significant southerly swell makes the bay surgy and dangerous. 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 in calm conditions, snorkel the reef edges and gutters in the bay, and stay inside the bay rather than venturing into open water around the cape. Agree a turn pressure before descending (half gas, or a third where current is likely), carry a DSMB, and make a 3-minute safety stop at 5 m.

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.