Marine and coastal tourism constitutes one of the largest and fastest-growing segments in tourism. Growth in marine tourism is now furthered through the 'blue growth' imperative, which this article problematises. The paper argues that there are already existing sustainability issues related to the marine tourism sector. These problems could be exacerbated if growth is additionally boosted. Since the social sustainability consequences of the growth of marine tourism are less known in the sustainability science literature, this paper thematically synthesises these types of sustainability problems in particular, as presented in the tourism studies, and brings them closer to sustainability science readers. The cases of cruise tourism, ecotourism, and tourism in marine protected areas, and community-based tourism studies are examined, wherein the latter represents a critical case for social sustainability matters. The paper reports several social and environmental injustices, produced through structural forces, and a manipulated access to natural resources, health services, and healthy environments. Social sustainability issues are most obvious in cruise tourism; however, also tourism in marine protected areas, ecotourism, and community-based tourism are not unproblematic. Thus, blue growth initiatives should be carefully examined and questioned.