This report conducts an assessment of the Marine Transportation System (MTS)functions and condition, threats to its continued operations, and vulnerabilities that make the threats more likely to materialize, within a risk and resiliency analysis framework developed for this assessment. Within this framework, the study also evaluates the inherent elements within the system which mitigate the consequences of the MTS risk factors, and identifies technology deployment and policy solutions that would enhance MTS sustainability and resiliency.