A fast method is presented for calculating the wavefields from initialized leaky Lamb waves on plates immersed in sufficiently light fluids. The method works by precomputing the dispersion relation and attenuation, and propagating the wavefields in the frequency domain. An angular spectrum approach is used to include leakage into surrounding fluid. Compared to matching FEM simulations, the computations are performed in the order of seconds, rather than hours. The method also benefits from being much easier to set up correctly, but is on the other hand less general in that it cannot handle e.g. scattering from defects. The correspondence is shown to be good for the case of interest.
