We examine the global spread of Masters Swimming (MS) focusing on the economic, social, and demographic conditions associated with its initiation in the United States and its international growth. We characterize MS as a modern sport and look at its subcultural form, organizational structure, practices, and early pattern of organizational growth from bottom to top. Then we describe the top down role of La Federation Internationale de Natation Amateur (FINA) in supplying legitimacy, resources, organizational coherence, and corporate sponsors to spread the sport among FINA members. By establishing mutually beneficial relations with corporate sponsors, MS rapidly commodified and diffused to countries and territories with middle to high socio-economic development.