Investigation of the dynamics of internal gravity waves often includes the interrelationship between wave amplitudes, wave speeds, and wavelengths. These relationships are commonly thought of as dispersion relations. Because internal gravity waves are the result of nonlinear dynamics dispersion relations are a challenge to obtain in a quantitative sense. Model data for internal gravity waves in the Strait of Luzon are examined using Fourier and continuous wavelet transforms. Dispersion is qualitatively evident in the results and the investigation is extended to include quantitative assessment of the dispersion. The results are compared to results from Korteweg D'Vries theory. Good agreement is obtained for dispersion estimates using wavelet analysis and those from KdV theory