20231005 14512000 1.0 TRUE Navigation Aids DoT (DOT-004) Western Australia uses an internationally recognised uniform coding system of navigation marks known as the IALA buoyage system A. Navigation marks are the equivalent of road signs on highways. Please contact the Department of Transport, 1 Essex Street, Fremantle WA 6160 or by emailing cdc@transport.wa.gov.au for more information. Department of Transport (WA)