The use of ultrasound for immersion mode quantitative nondestructive evaluation depends on our ability to model the interaction of the incident beam with the water-solid interface. The effects of surface roughness on the inspection process may be crucial. For example, ultrasonic images of interior flaws will be degraded due to the random fluctuations in the wave front of the incident field [1,2]. Similarly, surface roughness also affects the characterization of porosity in solids from the ultrasonic attenuation [3] since the attenuation is commonly determined by comparing the reflection from the backsurface with that from the front surface of the part.