The results of the Namibia Expedition 1992, carried out by the Museum für Naturkunde der Humboldt-Universität Berlin and the State Museum of Namibia, Windhoek, supplement by the results of several former missions of the Museum Alexander Koenig, Bonn, and the Transvaal Museum, Pretoria (Kalahari Expedition), are listed and discussed concerning the water beetle families Spercheidae and Hydrophilidae. Altogether 4 species of Spercheidae and 81 species of Hydrophilidae are proved for Namibia and the Kalahari Desert up to now, including 5 species new to science described in this paper as Amphiops namibicus sp. n., Amphiops uhligi sp. n., Chasmogenus omissus sp. n., Helochares (Hydrobaticus) conformis sp. n., Laccobius uhligi Gentili sp. n.; one additional new species Berosus (Enoplurus) wewalkai described by S. Schoedl, Vienna, in a separate paper. Keywords: Insecta, Coleoptera, Hydrophilidae, Spercheidae, new species, species list of Namibia, zoogeography, Africa, Afrotropical region, Namibia.