The effects of source motion on an acoustic signal received by an underwater sensor or array of sensors are examined using ray theory and time series analysis. The signal was modeled for the passage of a constant depth source over several kilometers in range to include propagation both inside an outside of a convergence zone. The effects of radial and skew (nonradial) source motions are determined and selective fading is observed when the reception of a narrow‐band multiline signal of 200 ±1/2 Hz is investigated. The frequency, temporal and spatial coherences, and power spectra are calculated for the computed time series. Results show the effect of source placement in range and depth with a deeper source (450 m) having a broader spectrum and a much smaller coherence time than a shallower (100 m) source. Coherence bandwidths were only slightly affected by source position while spatial apertures were extremely large due to the simplified propagation model. Although the results for specific transducer separations are included, arguments based on multipath behavior with range generalize those results to the 500‐to 700‐km region.