The objective of this project was to improve the overall safety of ultra-deepwater or arctic floating platforms by implementing nonlinear effects in a state of the art software code that could be used by the industry. Better understanding of the effects in a state of the art software code that could be used by the industry. Better understanding of the effects of nonlinearity on floating platforms through research and development would inherently decrease the risks associated with implementing ultra-deepwater or arctic design projects. The objective was met through the development of a methodology and associated algorithms for the evaluation of ultra-deepwater floating platform performance under hazardous sea conditions. Numerical tools were developed and implemented for the computation of ultra-deepwater floating platform performance and safety for the extreme ocean conditions.