We present a technique for rectifying distorted imagery collected by an upward-looking, submerged camera for the purpose of reconstructing the above-surface scene. Radial surface slope is deduced near extinction boundaries separating regions of transmission and internal reflection. The radial slope measurements are fit to an estimate of the distorting surface, which is recursively improved so as to minimize the quadratic measurement error. The surface is assumed to obey linear wave dynamics. After surface estimation, the above-surface scene is reconstructed by inverse ray tracing. Results of testing the wave estimation and inverse-ray tracing algorithms against simulated underwater data are presented.