This article proposes the marine ethnography of an anthropological investigation carried out in and from the body in the Red Sea, Saudi Arabia, from 2011 to 2016. This research process presents the body as a place of situated and porous cultural adaptation, articulating what happens inside and outside the body, between the particular and the general. Situated, because relating the particularity to being in the compound of KAUST (King Abdullah University of Science and Technology) and the generality of being in a restrictive and authoritarian country such as Saudi Arabia. Porous in relation to the context, because showing the assimilation of the Saudi gender systems in the investigating body through a marine ethnography product of the comparison of the social landscapes "sand" and "sea", and the perceptions, emotions and movements observed and embodied in both ethnographic experiences, inside and outside the Red Sea. On the other hand, the article presents the sea, as the landscape of expansion between the empirical and the conceptual, between the ethnographic texts gathered in the sand and the anthropological theorization.