The present study was conducted with the aim of designing and validating a sea-based economic development model based on branding in the country's maritime free zones. This study is an applied-developmental study from the perspective of purpose and a cross-sectional survey regarding data collection method. To achieve the goal, an exploratory mixed research design was used. The participants in the qualitative section included university professors and managers of Qeshm Free Zone Organization and Qeshm Ports and Maritime Administration. Sampling was done by purposive method and theoretical saturation was obtained by 19 interviews. In the quantitative section, the views of 125 managers and experts of the Free Zone Organization and the Qeshm Ports and Maritime Administration were used. The sample size was determined by effect size and test power method and cluster-random sampling was used. The data collection tools were semi-structured interviews, structural-interpretive modeling questionnaires, and researcher-made questionnaires. To analyze the data, the qualitative thematic analysis method with Maxqda software, the structural-interpretive modeling method with Micmac software, and the partial least squares method with Smart PLS software were used. The results of the research showed that the components of location branding, internal branding, co-branding, and digital branding affect the components of sea-based brand performance and sea-based commercial performance. The two mentioned components also affect the components of marine ecosystem development, sea-based export development, social development, and…