Blue kilometre signs mark approximately every two kilometres along the Murray and were erected during the 1990s by the NSW Waterways Authority and Tourism SA. After the 1870 survey of the Murray River members representing miles from Albury were carved into trees along the banks of the river between Albury and Wentworth.
Occasionally these trees can still be found and some are marked on the Charts. The distances represent kilometres to the Murray Mouth. In the event that something happens on your houseboat trip they are an excellent way to tell your houseboat company of your approximate location.