Although the blue economy has the potential to play a role in sustainable marine development, to date there have been relatively limited practices to implement the blue economy concept on Untung Jawa island. This research aims to identify potential sectors to support blue economy development, analyse the elements involved in blue economy governance, and analyse the structural model of these elements to improve the Blue Economy Development Index in Indonesia. This research employed a mixed methods approach to achieve these objectives: policy and institutional analysis, semi-structured interviews with blue economic actors, and field surveys. The analytical method used was interpretive structural modelling. The findings of this study indicate the existence of six blue economy sectors on Untung Java Island: shipbuilding, fishing, aquaculture, marine tourism, marine transportation, and seawater desalination. The results indicate that the enforcement of laws and regulations related to the blue economy as a key element, followed by the element of stakeholder support related to the blue economy. Meanwhile, for the institutionalization of sustainable blue economy governance, this study found government leadership and commitment as the key institutional element of key institutional elements of blue economy governance.