Bill's Bay is the main beach at Coral Bay — a wide curve of white sand fronting a shallow turquoise lagoon, with the reef break visible offshore. The water is calm, sheltered, and clear enough that you can see fish from the shore without a mask. Walking south along the beach for ten minutes brings you to a series of bommies (coral heads) sitting just off the sand, where snorkelling is reliably excellent.
The bay is also a turtle nesting beach. Green and loggerhead turtles haul out to lay eggs between November and February, and hatchlings emerge from January through April. The northern end of the beach is closed seasonally during nesting; volunteers from the Cape Conservation Group run early-morning monitoring walks that anyone can join.