This study examines the organizational factors, leader-member exchange (LMX), and team-member exchange (TMX) affecting seafarers’ safety citizenship behavior (SCB) in respect of seafaring lives. Accordingly, we investigate the moderating effect of the safety climate on these relationships. Questionnaire surveys were collected from 283 seafarers in Taiwan’s shipping industry. Partial Least Squares-Structural Equation Modeling (PLS-SEM) was employed to test the hypothesized causal relationships and moderating effect. The results showed that each of the safety climate, LMX and TMX were significantly related to the seafarer’s SCB; specifically, the safety climate strengthened the relationship between LMX and the seafarer’s SCB, but its effect on the relationship between TMX and seafarer’s SCB was insignificant. This study contributes to the academic literature on safety since it demonstrates the moderating role of the safety climate in linking LMX, TMX, and safety citizenship behavior that has been underestimated in previous research. We suggest that marine masters and shipping companies should specifically consider the influence of LMX and TMX within a ship, and reinforce a safety climate to improve safety performance.