Please Note: This information is provided in good faith but not guaranteed.
Always check with the appropriate Government Department for any changes and corrections.
Queensland
All ships with a motor or auxiliary of more than 3 kW (over 4 hp) must be registered when on the water.Your ship will be allocated registration symbols. These must be clearly visible in plain characters in a contrasting colour to the hull of your ship. The size of the characters depends on the type of ship and must be able to be read from a distance of 30m away. Ships not capable of planing must have characters a minimum of 75mm high on both sides or on the stern. Ships capable of planing must have characters a minimum of 200mm high on both sides. Personal watercraft (for example a jet ski) registration symbols must be displayed on both sides at least 100mm high easily seen while the craft is underway.
NSW
For mechanically propelled vessels registration numbers must be shown on each side of the vessel in figures at least 150mm high and must be clearly distinguishable at a distance of 60m while underway. They should be located on the forward section of the vessel's hull or topsides on each side of the vessel. For sailing vessels registration numbers must be shown on the transom, or on both sides of the hull adjacent to the stern. In the case of multi-hull craft, the numbers must be on the outer faces of the external hulls adjacent to each hull's stern. The figures must be at least 100mm high and in a position where they can be seen when the vessel is underway. Note: a 'sailing vessel' means a vessel which has sails as its primary means of propulsion.Personal watercraft (PWC) must have their registration numbers on each side of the craft in figures at least 100mm high, where they are clearly visible when the vessel is underway. The colour of Rego Numbers on a vessel should be of contrasting colour to the boat's hull. Black numbers are the standard on a light-coloured hull, however white or pale coloured figures should be used on a dark coloured hull.
Western Australia
Power boats: midship on the side or super-structure of a boat / vessel where they are clearly visible and not under the flare of the bow - 150mm high. Yachts: on the side of the hull immediately forward of the transom - 50mm high. Tender: must have its parent vessel's number displayed on each side of the boat, forward of the transom. The registration identification label is to be affixed on the port (left) side of the vessel, outside and immediately adjacent to the registration number.
Tasmania
You must attach your registration label in a position that is visible from outside the vessel. You must also display your registration numbers,150mm high, on each side of the vessel.
Victoria
The boat identification numbers must be painted or displayed on the hull of the boat on each side of the bow as high as practicable above the waterline in characters that are no less than 150mm high; and in proportionate breadth; and coloured in contrast to the surface.
South Australia
The registration number issued to the boat must be painted or displayed on both sides of the bow in a contrasting colour to the surface in figures at least 150mm high, painted on or displayed using stick-on numbers clearly legible at a distance of 50m while the vessel is underway in clear weather.