Many maritime incidents could have been prevented by the use of a navigationassessment, which, through careful observation, evaluates how the navigation of a ship is being conducted. An effective assessment should take place over several days & provide practical feedback to the bridge team as well as guidance to shore-based management. This handbook provides a step-by-step guide that will enable the assessor to carry out a fair, objective & positive assessment that properly takes into account human element issues. Case studies of maritime accidents & incidents provide valuable learning points. The book is also intended to help mariners understand the assessment process. If it is properly conducted, an assessment will provide insights that contribute to navigators’ continuing professional development.