In this paper we examine the present state of underwater systems including both machine and humans, identify problems associated with these systems and how fuzzy logic can be used to extend the functionality and safety through risk analysis. Specifically in this paper we examine autonomous underwater vehicles investigating navigational issues in a myriad of locations and conditions. We also discuss issues associated with human divers and propose a new sensor acquisition technique to facilitate making diving safer as well as reviews techniques for implementing a new decompression algorithm in hardware.