This paper conducted the synchronic and diachronic comparative law studies between the relevant legislations in both Korea and Japan to confirm the adequacy of the penal provisions under the Korea`s Ship Safety Act. Questions have been repeatedly raised about the excessive punishment in the maritime laws, especially the Ship Safety Act. To reveal this clearly, this paper attempted a multidimensional analysis through comparison between current Ship Safety Act&Criminal law of Korea, between Ship Safety Act&Criminal law of Japan, and between those two countries. In particular, to keep track of the diachronic changes, examined the history of relevant legislations. The main content of this paper is as follows. First, the maritime law, which includes the Ship Safety Act, reveals excessive and symbolic criminal law issues. In order to promote understanding of the problem and for improvement of the system, it is necessary to introduce a comparative methodology that involves in-depth social analysis reflected in the legislation rather than simple comparison. Second, as a result of synchronic comparing between current Ship Safety Act & Criminal law of Korea and Japan, it can be perceived that the penal provisions under Korea's Ship Safety Act are not appropriate compared to the Korea`s Criminal law, and that they are clearly excessive compared to Japan's case. Third, through the diachronic analysis of the changes in the Ship Safety Act of Korea and Japan since the initial enactment in relation to the occurrence of major maritime accidents showed a clear symbolic tendency in the recent provisions of the Ship Safety Act of Korea. In particular, it is also confirmed that the actual effect of the symbolic legislative trend is insignificant. Fourth, it is suggested that the overall revision of the penalty regulations in Ship Safety Act of Korea is inevitable in order to solve the problems identified above.