This paper investigates the process of marine accident analysis for the official
interpretation to define the rate of defects of vessels in the intended case and proposes
the pairwise comparison approach which is frequently used in AHP method. The
assessment of marine accidents is a complicated and sophisticated problem which
needs a professional and fair judgment based on the existing evidences and navigational
specs. However, human judgment is limited and it is usually problematic to evaluate
several aspects of a case. The pairwise comparison method is first suggested to simplify
decision making process for ranking or selecting an item among the alternatives and it
is an essential part of analytic hierarchy process. By utilizing the pairwise comparison,
the defect rate of a snapshot of marine accident is calculated in a stepwise approach.