Introduction. In maritime educational institutions, the existence of a system of continuous professional and legal training of cadets is relevant in connection with the implementation of a competent approach to the formation of professional and legal competencies. The purpose of this article is to study the professional, personal qualities of the cadet, affecting his professional and legal competence and readiness for professional and legal activities after graduation. They are of interest, criteria and indicators of behavior for assessing the professional, personal qualities of a cadet. The information obtained on the basis of the results of the experimental work on testing and practical implementation of the system allows us to assess the levels of formation of professional and legal competencies, which indicates its effectiveness. Materials and Methods. The experiment was attended by cadets of the 1st, 3rd, 5th courses of the specialty "Navigation" in the amount of 150 people. The Mann-Whitney U test criterion is used as a method of statistical processing. Assessment of the levels of formation of competencies was carried out by the method of questionnaires, testing, surveys, developed by the authors on the basis of the methodology of N. P. Fetiskin, G. M. Manuylov. The description of the level of each personal professional and legal competence included distinctive characteristics and a description of their manifestations in the behavior of the cadet, the so-called behavioral indicators. Results. According to the results of the questionnaire survey, it was revealed that the readiness of cadets for professional and legal activities does not always meet the established requirements. So the general level of legal competence of a graduate of a maritime university is 24 % of 50 people surveyed, that is, 12 people. The implementation of the system of continuous professional and legal training of cadets at the maritime university proposed by the authors allows not only to determine the content of legal disciplines, but also to introduce new forms, methods, means of training, to develop criteria and behavioral indicators for assessing the professional, personal qualities of the cadet that affect his professional and legal competence. Discussion and Conclusions. The results of the study at the maritime university based on the results of the experimental work carried out on the approbation and practical implementation of the system make it possible to assess the levels of formation of professional and legal competencies, which indicates its effectiveness.