Multibeam bathymetry raw data using the ship's own Kongsberg EM 122 multibeam echosounder was almost continuously recorded during RV METEOR cruise M123. Data was recorded on 22 days between 2016-02-05 and 2016-02-26. This dataset mostly contains an elongated transit survey parallel to the South African coastline and a survey of the coastal area of Mozambique. The approximate average depth of the entire dataset is around 1200m. During data acquisition the Kongsberg EM 712 multibeam echosounder was occasionally switch on simultaneously, thus interference between both systems may have occurred during the survey.The data are archived at the Federal Maritime and Hydrographic Agency of Germany (Bundesamt für Seeschifffahrt und Hydrographie, BSH) and provided to PANGAEA database for data curation and publication. The complete record of ancillary sound velocity profiles (SVP) from the cruise archived at the BSH are added to this dataset. These individual SVPs files however could not be clearly related to any event (ship's log entry), therefore position and datetime of SVP data acquisition is rather uncertain. Data analysis of the raw multibeam data revealed that SVP occasionally has been changed during the cruise.This publication is conducted within the efforts of the German Marine Research Alliance in the core area "Data management and Digitalization" (Deutsche Allianz Meeresforschung, DAM).Data are unprocessed and therefore may contain incorrect depth measurements (artifacts) without further processing.Data can be processed e.g. with the open source software package MB-System (Caress, D. W., and D. N. Chayes, MB-System: Mapping the Seafloor, http://www.mbari.org/products/research-software/mb-system/, 2021).

These data should not be used for navigational purposes.Data publishing was realized by Daniel Damaske, MARUM - Center for Marine Environmental Sciences (University Bremen).