In this present work, a detailed verification and validation study is presented for a computational fluid dynamics (CFD) framework that aims to predict fluid physics and forces associated with naturally inspired marine propulsion. This approach involves comparing experimental datasets to their simulated counterparts and evaluating the numerical accuracy of the CFD toolset. In this manner, the error and uncertainty of the predictions from the CFD toolset can be established, which both convey the accuracy of the model and gives additional confidence in the underlying physical character of undulation-based propulsion. Validation efforts include simulation of a D-tube shedding a von Kármán vortex wake, a heaving and pitching foil generating thrust, and a traversing flat plate which is abruptly heaved and pitch. For all cases, mesh and time-step refinements are employed to ascertain numerical uncertainty. Although not yet complete, we also aim to roll up uncertainty from experiments and input uncertainties.