Abstract
The capture width for mechanical and radiation power of the multi-float wave energy converter M4 has been determined through a linear diffraction-radiation model. The 134 version is modelled with four power take offs (PTOs) in irregular waves. The combined mechanical and radiation damping gives the total power capture from the incident wave propagation, not previously considered, and is important for wave farm analysis. The wave power transmission through one and two rows of devices normal to the wave direction is estimated and with a spacing of about 6 wavelengths power transmission can be as low as 20% and is about 50% over a broad band of periods. Total power absorption is greatest without PTO which would be appropriate for large or extreme waves. Such large wave power absorption gives the potential for coastal protection in addition to energy generation.