Abstract: The English language is the mode of instruction used in the Philippines, particularly at the tertiary level. However, given the wide variety of languages spoken by various ethnolinguistic groups in the country, it is not uncommon for a teacher to find herself handling students from different linguistic backgrounds and different levels of proficiency in English as their second language. This study was conducted to determine the relationship between the level of attitude and the academic performance of maritime students in their research courses when instructors demystify the class instruction into the Cebuano-Visayan language. The researcher employed the descriptive correlational method of research with the use of a validated researcher-made questionnaire. A total of 100 maritime students in the University of Cebu- Maritime Education and Training Center were surveyed. The results showed that students have a very positive attitude toward Cebuano-Visayan language demystification in-class instruction in their research courses. The test of hypothesis of the attitude of the respondents toward Cebuano-Visayan language demystification was found as not significantly correlated with their academic performance in their research courses. Thus, despite this, the researcher concludes that Cebuano-Visayan language demystification in research courses improves the overall learning experience for students.