Boat registration in Australia usually follows the engine, not the length. Like licensing, it is state-specific and turns on whether the vessel has (or can carry) a propulsion engine.
Victoria registers any boat with an engine capable of propulsion, explicitly including electric e-foils. WA registers any vessel that is or can be propelled by mechanical power, including sailing vessels capable of carrying a motor. Tasmania registers at the 4 hp threshold. NSW and Queensland set their own thresholds, worth checking directly.
The Crew reads your state’s rule against your actual vessel (engine, type, length) and tells you whether registration applies, and flags the edge cases, like an electric motor on a tender, that people miss.
The Crew checks the propulsion-engine trigger for your state against your vessel and flags the edge cases (electric motors, sail vessels that can carry a motor).
General information for Australian operators, current as of 2026-10-11. Rules change and recreational rules vary by state. Always confirm against the source(s) linked above (your AMSA, Australian Sailing or state maritime authority). This is not legal advice.