In immersion ultrasonic testing, a beam of sound must pass through a liquid-solid interface before it can interact with subsurface defects. In modern quantitative NDE studies, it is essential to know the beam properties in the solid so that flaw scattering variations, transducer diffraction corrections, etc. can be estimated. Using high frequency asymptotics and the method of stationary phase, we show here that analytical expressions can be derived for the wavefield radiated by a piston transducer, where the transducer is oriented normal to a plane liquid-solid interface (Fig. 1). In the main beam of the transducer these expressions will be shown to be equivalent to the solutions Schoch obtained for a single fluid medium [1].