The methodologies and processes outlined in this guide are for performance-based analyses of escort scenarios. This means that the acceptability of a vessel (or combination of vessels) for escorting is based upon the ability to control the disabled ship in accordance with specified performance criteria. This guide addresses four selected performance measures: Towing—the ability to tow the disabled ship under specified parameters, Stopping—the ability to stop the disabled ship within specified parameters.Turning—the ability to turn the disabled ship within specified parameters and Holding steady—the ability to hold the disabled ship on a steady course under specified parameters. The “specified parameters” are additional details that must be factored into the performance analysis. These parameters might be specified by a regulatory agency imposing the escort requirement, by a study group evaluating the feasibility of escorting in a particular waterway, or by the ship or escort vessel operators themselves to define the performance envelope of their vessels. Some examples of these parameters are: A ship transit speed (at the moment of failure), The failure scenario (rudder failure alone, or simultaneous rudder/propulsion failure, degree of failure, and so forth), Navigational constraint within which the disabled ship must be brought under control (such as allowable advance and transfer, cross-track error, and so forth), Wind, current, and sea conditions and Time delays, failure recognition, decision making, escort vessel notification, escort vessel positioning, achieving full power, and so forth.