Nomenclatural and distributional notes are given for 15 described species of marine Gerridae, 1 species of Asclepios and 14 species of Halobates. Two new species are described, Halobates herringi and Stenobates insularis.

This is the first of a series of publications planned as guides to aquatic Heteroptera of Singapore and Peninsular Malaysia to be published in the Raffles Bulletin of Zoology. A key to families and a list of known genera with number of described species for each genus are given.