The hantavirus cluster reported in May 2026, associated with expedition cruise travel in the South Atlantic, highlights a rarely examined dimension of maritime infectious-disease preparedness: the movement of international travelers between semi-confined vessels and wildlife-associated settings. This narrative review examines hantavirus infection as a travel-associated zoonotic risk rather than a conventional shipboard outbreak. It summarizes hantavirus microbiology and transmission, with particular attention to rodent-associated environmental exposure, early clinical recognition, and the exceptional concern posed by Andes virus. The review also evaluates how shore landings, wildlife-associated excursions, delayed symptom onset, and post-disembarkation passenger dispersal may complicate exposure reconstruction and public-health response. Molecular diagnostics, genomic investigation, environmental assessment, and One Health surveillance are discussed as key tools for distinguishing shared shore-associated exposure from possible secondary transmission. In conclusion, this review identifies a preparedness gap at the interface of maritime travel, zoonotic ecology, and international surveillance. However, delayed diagnosis, severe disease progression, and geographically dispersed exposure can still complicate early recognition and response.