Bill's Bay is Coral Bay's front yard: a calm, sheltered lagoon where a thick blanket of coral gardens lies close to the main beach. Wikivoyage describes the bay as a protected green zone with impressive quality, variety and quantity of coral and marine life, where turtles, dolphins, mantas and reef sharks are common.

The bay suffered in March 2022, when a low-oxygen event following the coral spawn killed fish and damaged coral; recovery has been ongoing since. Snorkellers still find coral patches, reef fish, turtles and rays within an easy swim of the sand.

About Coral Bay: the town is a small resort settlement on Bill's Bay at the southern end of the Ningaloo Coast, about 150 km south of Exmouth. The outer reef lies close to shore, so both lagoon snorkels and outer-reef dives are short boat rides away, and Coral Bay is home to Western Australia's largest resident population of reef manta rays, seen year-round. Much of the water around town lies within the Maud Sanctuary Zone, where fishing and collecting are prohibited. Advanced divers favour the 'cuts', where open-ocean water funnels through gaps in the reef and brings in sharks, mantas and pelagics, while the calm lagoon suits training and beginners. The 2025 marine heatwave affected northern and central Ningaloo most; southern areas including Coral Bay sustained less damage, according to AIMS.

Planning notes: this is primarily a snorkelling site. Expect to spend most of the dive around 3 m, with a maximum of about 5 m. It is a shore-access site that can be visited independently when conditions suit. Best season: Year-round (mantas year-round; whale sharks March–July; humpbacks July–October). Traffic: very popular (dived daily).

Park in Coral Bay town and walk to the main beach on Bill's Bay. Enter from the sand; coral begins a short swim from shore. Stay clear of the boat channel and moorings.

Coral Bay is 150 km south of Exmouth via the Minilya–Exmouth Road; the town is compact and everything is walkable from the caravan parks and resort. Gear hire is available in town. The swimming area is directly in front of the main car park and the Bill's Bay beach shelters; walk in from the sand.

Coral Bay's lagoon is protected by the outer reef and faces north-west, so it stays calm in the prevailing south to south-westerly winds that close exposed coasts; the outer-reef and passage sites, however, need low swell and light winds. The afternoon south-westerly sea breeze (often 15–25 knots in spring and summer) chops up the outer sites, so dives run in the morning. Tidal flow through the passages can be strong on springs.

Visibility is usually 10–20 m, lower after the March coral spawn (in March 2022 a spawn-related low-oxygen event killed fish and coral in Bill's Bay). Cyclone season November–April; stingers possible in warm months.

Snorkel from the main beach out to the coral, staying inside the swimming area and away from the boat channel.

Independent; glass-bottom boat and snorkel tours also operate in the bay.