Customer satisfaction is a critical indicator of institutional performance, particularly in higher education and maritime training institutions where service experiences directly influence users’ perceptions of institutional quality. However, limited empirical research has examined how service quality influences customer satisfaction across the diverse customer groups served by maritime higher education institutions, including students, training participants, and student officers. This study addresses this gap by examining the influence of service quality on customer satisfaction at Merchant Marine Polytechnic of West Sumatera and identifying service dimensions that require improvement. A quantitative survey was conducted involving 314 respondents selected through probability sampling from the Polytechnic’s customers in 2025. Data were collected using questionnaires and analyzed using simple linear regression and a t-test. The findings indicate that service quality has a positive and significant influence on customer satisfaction, demonstrating that improvements in service delivery contribute substantially to enhancing customers’ overall satisfaction. The study contributes to the service quality literature by providing empirical evidence from a maritime vocational higher education context, where service users have diverse educational and training needs. Practically, the findings provide a basis for the Polytechnic to strengthen service delivery, particularly in aspects requiring improvement, such as tangibles, reliability, responsiveness, competence, courtesy, communication, and understanding customers. The findings also suggest that institutional quality improvement policies should prioritize continuous service evaluation and customer-oriented improvement to enhance satisfaction and support the competitiveness of maritime education and training institutions.