This document outlines methods and procedures for three situations involving altering course and/or speed of a ship to avoid collision with another ship detected on radar. It provides instructions on how to calculate range to closest point of approach (RCPA), time to closest point of approach (TCPA), target speed (TS), motion (MRM, DRM, SRM) and changing aspects. Examples are given of plotting vectors to determine a new course that maintains a 3 mile CPA when either reducing speed, maintaining course and speed, or altering both course and increasing speed. The document teaches how to analyze radar contacts and calculate new courses and speeds needed to avoid collisions.