Unmanned Underwater Vehicle (UUV) simulations that include environmental impacts to vehicle performance can increase mission success rates and decrease risk for the vehicle operator. In this thesis, a UUV power model and hydrodynamic model are combined in a simulation environment to create a framework for predicting vehicle performance in high currents. Field data from fixed sensors and UUV missions are used to validate the models used in the simulation tool. Results of the simulation tool are used to predict vehicle failure events, to study vehicle performance metrics, and are translated into a Tactical Decision Aid (TDA). The TDA is a powerful tool to mitigate risk in the pre-mission planning process. Two case studies in the Mission Bay, CA region are presented to demonstrate the utility of the TDA.