Floating breakwaters provide an alternative form of wave barrier to conventional rubble mound and caisson breakwaters in low to moderate wave climates with relatively short wave periods. This report reviews the literature on floating breakwaters and discusses existing and potential uses of floating breakwaters in Australia. It also contains results of a field programme which measured the prototype performances of two breakwaters in Sydney Harbour and compared them with those predicted using physical models. The programme was carried out using low cost wave measuring equipment specially developed for this study.