SWAN propagates offshore wave conditions to the nearshore, and can account for: Wave propagation in time and space, shoaling, refraction due to current and depth, frequency shifting due to currents and non-stationary depth. Wave generation by wind. Three- and four-wave interactions. Whitecapping, bottom friction and depth-induced breaking. Dissipation due to aquatic vegetation, turbulent flow and viscous fluid mud. Wave-induced set-up. Propagation from laboratory up to global scales. Transmission through and reflection (specular and diffuse) against obstacles. Diffraction.