By employing primarily the Kendall's Concordance Test, the paper attempted to conduct an experts' evaluation on the interaction among the agents in Busan marine tourism cluster and recommend some measures for policy consideration for the cluster's activation. For this purpose, a conceptual framework was developed to guide the assessment by using inter-agent cooperation and network approaches regarding the nature of the marine tourism cluster. Such factors as cooperation, competition, relationship marketing, and networking were identified as critical. Findings of the study imply that Busan marine tourism cluster is at its embryonic stage and needs desperate measures for improvement in the inter-organizational cooperation and networking, the major regional characteristics that determine the competitiveness of marine tourism.