In addition to the canoe or kayak canoeists will require a paddle, personal floatation device ("PFD") and appropriate clothing. More information can be found here.
The general rule is "you got yourself into this: you get yourself out of it." Safety is risk management and knowing your limitations and working within them. The Australian Canoeing Safety Guidelines will give you an outline on what you should do (or not do).
Canoeists, like others who use the outdoors for recreation, have a responsibility to minimise their impact on the natural environment and on public and private property. Canoeists should always comply with the Canoeists Environmental Code .