The current study investigated the intercultural communication challenges among Indonesian seafarers with foreign crews at international shipping companies. Data collection was conducted through a mixed-questionnaire method, with each questionnaire consisting of 10 items distributed in Google Forms to 171 respondents. The findings revealed that the language barrier was a significant issue among Indonesian seafarers to communicate and socialize with onboard multinational crews, which was mainly overcome through body language. Indonesian seafarers’ acceptance of onboard diversity rendered them to be more sociable, which was identified as a positive attitude. However, it cannot be denied that the fact of low communicative competence has impacted social life interactions and work for some seafarers. Resultantly, pertinent Indonesian maritime education and training institutions should adequately prepare seafarers and cadets with relevant work skills and English linguistic competence. This research aims to shed new light on the development of maritime and seafarers’ research.