Among the million or so insect species known, only a few thousand are found in marine habitats. The genus Halobatesis almost exclusively marine and is unique in having the only known species to live in the open ocean. Of the 46 Halobatesspecies described, only five are completelyoceanic in habitat, with the majority of species living in coastal areas associated with mangroves or other marine plants. This review presents a brief historical account of the genus and providesinformation on various aspects of its life history, ecology, special adaptations, distribution, and biogeography. Distribution maps of the five oceanic species as well as several of the more widely distributed coastal species have been updated. The phylogeny and evolution of Halobatesbased on morphology and recent molecular data are also discussed. A key to all known species of Halobatesand related genera and a checklist of all species and their distributions are included as appendices.