A modelling approach is described in which time-domain underwater-acoustic source functions are generated using a model that predicts the motion of air-bubbles generated by mini-airguns operated at various pressures. These time-series are Fourier-transformed to produce frequency-domain descriptions of the source. These are combined with complex transfer functions describing the propagation of sound in shallow-water waveguide geometries so that source spectra can be converted to received spectra by a simple multiplication process for specified source and receiver positions. Received spectra can be inverse-Fourier transformed to produce time-series of received signals. Calculations are performed to yield three acoustic variables: one pressure and two particle velocities (in the radial and vertical directions). Time-series are shown for a test environment in which total acoustic fields are made up of contributions from waterborne and bottom-interacting paths. © 2018 80th EAGE Conference and Exhibition 2018 Workshop Programme.