What to watch for rockpooling in Australia
Australia has the richest shore fauna on this site and is the only country with a genuine reason to keep your hands out of the water. The four animals to know, and where the good shores are.
The one rule that is specific to Australia
Do not put your hands anywhere you cannot see, and do not pick anything up.
That advice is good manners everywhere else on this site and a safety rule here. Australia is the one coast in this directory with intertidal animals that can seriously injure a healthy adult, and every one of the incidents that happens each year involves somebody handling something or reaching blind into a crevice.
The four to know
The blue-ringed octopus is small enough to fit in a palm, and lives in rock pools and under rocks right around the Australian coast. It is not aggressive and the rings only flash blue when it is alarmed, which is to say when it is already in a hand. Its venom is tetrodotoxin, there is no antivenom, and bites are painless. Do not pick up a small octopus, and do not pick up a shell without checking what is in it.
Cone snails are handsome patterned cones in the tropical north and they fire a harpoon. Some species are dangerous to humans. The rule is the same: an attractive cone-shaped shell in northern Australia is not a souvenir.
Stonefish sit motionless in shallow tropical rock pools and look exactly like a stone with weed on it. The spines go through a thin sole. This is the single best argument for proper shoes on a northern shore.
Bluebottles are not in the rock pool but on the beach you cross to reach it, and they sting after they are stranded and after they look dead. Do not let children pick up the blue balloons.
Two different coasts
Australian shores divide into two things. The southern rock platforms of New South Wales, Victoria, South Australia and Tasmania are temperate, wave-cut and comparable to a Californian or a Cornish shore, with waratah anemones, cunjevoi, chitons, sea stars and an excellent nudibranch fauna.
The northern and Western Australian reef flats are a different exercise: coral, giant clams, sea cucumbers, and the animals in the section above. Both are worth going to. Only one of them requires reef shoes.
When
The biggest tides follow the new and full moon here as everywhere, and the largest of the year arrive around the equinoxes. Which of them land in daylight depends heavily on where you are. The Australian coast spans thirty degrees of latitude and several tidal regimes, from the modest range of the south-east to the enormous ranges of the north-west shelf, where the water can move more than eight meters.
The practical answer is to check a local table for the specific shore rather than adopt a national rule, because there is not one.