Every southwest monsoon season, men and women from west coast fishing villages migrate to east coast villages, leaving their homes and their school-age children behind with kin. This monograph is an exploration of the motivations and aspirations that drive an internal process of seasonal fisheries migration. It focuses on the gendered livelihood patterns, collective identities and the social networks that enable or disable a long practice of seasonal coast-to-coast migration. It also examines the contestation of access to resources on the basis of a right to a tradition of migration among migrant communities and a right to ones own local resources among host communities. The study is based on a range of qualitative methods and a quantitative household survey conducted in two migrant sending communities in the Puttalam district and two migrant receiving communities in the Trincomalee district between 2016-2019. The monograph inquires the extent to which seasonal migration contributes to poverty reduction in fishing communities. It concludes that internal coast -to -coast migration is not primarily motivated by poverty or resource scarcity. Instead, it is an adaptive livelihood strategy pursued by men, women and youth in fishing communities in response to monsoonal weather patterns, as well as a way of life to fulfil a complex combination of material, relational and subjective wellbeing goals. It asserts that an understanding of the causes, processes and relations of internal seasonal migration can facilitate more effective policies and regulations governing the fisheries industry in Sri Lanka.