The goal of repeat imaging (detailed studies of prospects as new information is available) using PSDM is to generate new locations for both development and exploration targets. We present two case studies of repeat imaging and grid tomography in the Gulf of Mexico acreage. The first field (field H) consists of angular beddings truncating at the base of a thick salt. The second field (field T) consists of sediments under a salt of unknown thickness where well control shows only thin salt penetration. The up dip potential of the pay sands for both prospects had not been shown clearly in the previous depth processing. A careful model building approach with automated residual moveout estimation and 3-D grid tomography in the supra-salt area enabled us to estimate the sediment velocity properly. This helped us to reinterpret the top salt and base salt and enhance the sub-salt reflections. We provide two examples of the velocity model building and depth imaging in this area.