Vocational education and training (VET) concerns the cultivation and development of specific skills and competencies, in addition to broad underpinning knowledge relating to paid employment. VET assessment is, therefore, designed to determine the extent to which a trainee has effectively acquired the knowledge, skills, and competencies required by employers. Across a range of occupations, such testing has traditionally comprised a portfolio of practical on-the-job assessments, oral tests and laboratory tasks. In recent years vocational training assessment has increasingly adopted new computer-based assessment (CBA) methods and, as a consequence, consideration of the scope of computer-based assessments and their appropriateness for vocational training evaluation is timely. This paper examines the growing adoption of CBA within the safety-critical field of maritime education and training (MET), particularly, in relation to the summative assessment of seafarers for licensing purposes. It discusses the implications for validity, reliability and security. (Contains 3 notes.)