Blue Heron Bridge

The whole day is built around a tide table. Shops publish the window in advance, divers converge on the car park well before it, kit up at the rinse stations and walk down to the beach in a slow procession. On a weekend slack there can be dozens of people in the water at once, spread out between the two spans. Flags and floats are not optional here: a marked boat channel runs through the site, boats use it throughout, and divers are expected to stay well clear of it.

There is no reef to speak of. The bottom is sand and seagrass broken up by rubble, bridge pilings and dumped concrete, and everything worth finding is either sitting on that hard structure or buried in the sand beside it. The channel is scoured deeper and carries most of the flow, while the flats on either side sit in a few metres, shallow enough that air is rarely what ends the dive. Clarity swings with the tide, best on the flood and going milky once the ebb starts pulling lagoon water back out.

The diving itself is close to static. A good dive is measured in tens of metres covered rather than hundreds, working one rubble patch, one piling, one clump of grass at a time, and a guide who has been watching where the resident animals sit all week changes the dive entirely. Cameras dominate, along with the etiquette that comes with them: wait your turn at an animal, never move it, and keep your fins clear of the sand everyone behind you is about to search.

It rewards patience and a naturalist's eye, and is forgiving in every other respect: shallow, sheltered, walk-in, with showers, tables and shade at the top of the beach. Snorkellers see much of the same on the same tide. Anyone who came for structure, blue water or big fish will be bored quickly, and the reef and drift diving this coast is known for starts a boat ride offshore. Night diving is permit-controlled, so arrange it through a local shop rather than turning up after dark.