Continental boundaries have a shallow sloping bottom that changes to a steeper slope. Our laboratory acoustic models (simulations) have (1) a 11° slope that changes to a 50.5° slope and (2) a 35° slope change to a 59° slope. The surface and bottom of the acoustic model are dry wall construction board. The source is a spark and the receiver is a small microphone. The Biot–Tolstoy exact time-domain solution was used. [I. Tolstoy and C. S. Clay,Ocean Acoustics(American Institute of Physics, New York, 1987), 2nd ed., Appendix 5, and C. Feuillade and C. S. Clay, J. Acoust. Soc. Am.96, 501–514 (1994)]. The image-reflection and diffraction components depend on source and receiver locations. In model (1), source and receiver were within the 11° wedge and gave reverberations that were mainly from the 11° wedge. Source and receiver beyond the shelf break gave reverberations that were mainly from the 50° part of the model. In model (2), the source was up slope and receiver was near the break to observe diffractions. The finite number of arrivals (images) obeyed the Biot–Tolstoy rule. Experimental signals matched the theory in amplitudes and arrival times. Most reverberations were caused by multiple reflections in the wedge waveguide. The amplitudes of the image-reflection paths were an order of magnitude larger than the diffraction arrivals.