Wave-transmission and peak-mooring force design curves were generated for the Goodyear and Wave-Guard floating tire breakwaters from measurements on ⅛-scale and ¼-scale models using regular and irregular waves, and found to be in good agreement with available full-scale data. These curves may be used to determine the breakwater size needed to attenuate a given regular design wave to an acceptable level, and also to determine the maximum mooring load associated with this. A simple semi-empirical energy-dissipation model was developed and found to simulate measured wave-transmission characteristics with sufficient precision to be useful in many engineering applications; e.g., the ratio of transmitted to incident wave height is stated as an exponential function of wave steepness, ratio of wavelength to breakwater-beam-size, breakwater porosity, and a drag coefficient. An empirical relationship for the peak mooring force was obtained.