The purpose of this study is to develop a tool for measuring motivation for participation in marine sports and to verify its validity. In order to achieve this purpose, the data collected through in-depth interviews and open questionnaires were derived through the coding process, and the common meaning of the derived contents was classified and categorized by subject by applying the inductive method. Topics derived based on in-depth interviews and open questionnaire response data were classified separately with high frequency contents and used to create preliminary questions through a semantic process. First, item suitability was verified through descriptive statistics analysis and reliability analysis of the data collected using preliminary questions. Second, KMO fitness verification and Bartlett's sphericity verification were conducted to confirm whether it was suitable for conducting factor analysis, and exploratory factor analysis was conducted to extract sub-factors of the constituent concept. Third, the commonality coefficient for each sub-factor was calculated, and the internal consistency coefficient was calculated through reliability analysis. Fourth, confirmatory factor analysis was conducted to analyze the suitability of the factor structure for the latent and measurement variables extracted through exploratory factor analysis. Fifth, an independent sample t-test according to gender was conducted for marine sports participants in order to secure discrimination validity for the items finally confirmed through confirmatory factor analysis. Based on these results, it was developed as a measurement tool for motivation to participate in marine sports with a total of 28 questions, including 7 questions of nature-friendly interest, 4 questions of interpersonal relations, 4 questions of thrill, 5 questions of physical promotion, 4 questions of scarcity, and 4 questions of desire for achievement. With the development of a tool for measuring motivation to participate in marine sports, it is believed that it can be used as basic data in presenting the standards and directions of marine sports education programs and seeking policy measures to revitalize marine sports.