Comparisons are made of sound pressure and particle acceleration predicted by two methods in the vicinity of two arrays of marine-seismic airguns. Data describing the array properties and the environmental conditions are taken from test cases designed to facilitate intermodel comparison. The two propagation approaches, one based on method of images and the other on wave number integration, are shown to be capable of giving line-on-line agreement when the latter method implements the full form of the Hankel transform; when the more approximate Fourier transform is used, predictions are shown to differ at ranges of a few meters from the source.