Australia uses IALA Region A buoyage — red to port entering from seaward, the opposite of the United States. Every state test asks about it, and every night passage depends on it.
The direction of buoyage is the direction taken when approaching a harbour, river or channel from seaward. Around the Australian coast the conventional direction runs broadly clockwise: south down the east coast, west through Bass Strait, north up the west coast, east across the top. Paper charts mark it with a black arrow labelled "buoyage direction". Never assume — check the chart, because the convention reverses at a harbour entrance.
The memory aid taught in every Australian classroom: red to port returning to port. Red cans are cylindrical; green marks are conical. Port marks carry even numbers, starboard marks odd.
Red can. Red light, any rhythm except Fl(2+1). Even numbers.
Green cone, point up. Green light. Odd numbers.
Black, red band(s), two black spheres. White Fl(2). Two balls, two flashes.
Red and white stripes, red sphere. Navigable water all round — landfall and fairway buoys.
Yellow, yellow cross. Cables, pipelines, spoil grounds, data buoys — and racing marks.
Blue and yellow stripes, upright yellow cross. Alternating blue and yellow light. A new, unsurveyed hazard.
A preferred-channel mark is a modified lateral: the body carries the minor colour with a broad band of the major colour showing which channel is preferred, and a composite group-flashing light, Fl(2+1), in the major colour.
Cardinal marks
A cardinal mark tells you which side of a danger to pass. A north cardinal means "pass to the north of me". They are black and yellow, carry two black cones as a topmark, and the two things you must be able to read — cone arrangement and light rhythm — both follow a clock face. East is three o'clock: three flashes. South is six: six flashes, plus a long flash so you do not lose count. West is nine: nine flashes. North is twelve, the top of the clock: continuous flashing, uncounted.
The black band sits where the cones point. Both cones up, black on top. Both cones down, black on the bottom. Points away from each other, black at both ends. Points together — the wine glass — black in the middle.
Cones up. Black over yellow.
Q or VQ — continuous
Bases together. Black-yellow-black.
Q(3) 10s
Cones down. Yellow over black.
Q(6)+LFl 15s
Points together — the wine glass. Yellow-black-yellow.
Q(9) 15s
Very quick (VQ) rhythms carry the same counts on a shorter period — VQ(3) every 5s, VQ(6)+LFl and VQ(9) every 10s. The count, not the period, is what identifies the mark.