This study was conducted for the purpose of understanding the motivation for participation in marine sports tourism.To investigate this in detail, a total of 16 people were selected as an expert group, including representatives of marine sports tourism companies, marine sports experts, marine sports tourism participants, and marine sports tourism government officials. The results of a three-round Delphi analysis are as follows. The motivations for participating in marine sports tourism included self-satisfaction, psychological happiness, sociability, nature friendliness, physical health, and technology experience. Sub-factors of self-satisfaction appear to be dissatisfaction, healthy lifestyle, small joys in life, and pride.The sub-factors of psychological happiness were family happiness, leisure in life, meaning of life, and vitality of life. The sub-factors of sociability were found to be participants' communication, help in building friendships, intimacy, and positive interpersonal relationships. Nature friendliness was expressed as harmony with nature, unity with nature, comfort with the sea, and familiarity with nature. Physical health was expressed as health promotion, health driving force, fatigue relief, and physical strength improvement. Technology experience was expressed as skill improvement, skill acquisition, marine sports experience, and cultural experience.