The ballast water used as a ship's stabilizer when it is not loaded has a negative impact on health and the environment and even causes economic losses. One of them is caused by the pathogenic microbes in it. Therefore, the International Maritime Organization (IMO) enacted the Ballast Water Management (BWM) Convention to prevent the spread of pathogenic microbes that are very dangerous to health and the environment. The purpose of this study is to find out the extent of understanding of BWM Convention of the Deck and Engine Officer Class I and II in PIP Semarang. An analytical description and an overlap approach, including questionnaires, and in-depth interviews were applied to the research method. A total of 27 students from the deck and engine departments were included in the sample. According to the survey's findings, most participants don't fully comprehend the BWM contract. When being asked whether BWM was regulated, the correct answer was 0%. The right response when being asked whether Indonesia ratified the BWM was 0%. When being asked how the efficiency of BWM was 3.7% for the D-1 standard (ballast replacement) and 11.1% for the D-2 standard (ballast handling). However, 44.4% of respondents correctly identified the significance of treating ballast water, indicating that they are worried about the threat posed by this substance and that immediate action is required. The idea is to provide the student officers with knowledge via seminars, which could include training on maritime pollution or special ballast water training.