Multibeam echosounder (MBES) data recorded during RV Maria S. Merian cruise MSM15-1 between 12.04.2010 and 08.05.2010 in the Black Sea. The aim of this cruise was to quantify the concentration and uptake of oxygen at the anoxic boundaries in the water column and at the sediment water interface of the Black Sea, in parallel with the measurement of nitrogen, carbon, sulfur and iron fluxes (HYPOX project). . CI Citation: Paul Wintersteller (seafloor-imaging@marum.de) as responsible party for bathymetry and backscatter post-processing and its products. Description of the data source: During the RV Maria S. Merian cruise MSM15-1 the moon pooled Kongsberg EM1002 shallow multi-beam echo-sounder with a nominal sounding frequency of 95 kHz was utilized. 111 beams are formed for each ping while the seafloor is detected using amplitude and phase information for each beam sounding. For further information consult http://www.tdi-bi.com/downloads/EM1002_Product_specification.pdf. Fourteen bathymetric datasets were conducted during MSM15-1 with the EM1002. Though during the cruise the system was very reliable a systematic error exists in the outer starboard beams (approx. from beam 88 to 111). These were lowered about 1 m compared to the other beams in the fan. All surveys were run at a speed of 5 knots over ground. PI: Sebastian Albrecht (info@fielax.de). Description of data processing: Postprocessing and products were conducted by the Seafloor-Imaging & Mapping group of MARUM/FB5, responsible person: Paul Wintersteller (seafloor-imaging@marum.de). The open source software MB-System suite (Caress, D.W., and D.N. Chayes, MB-System Version 5.5, open source software distributed from the MBARI and L-DEO web sites, 2000-2012.) was utilized for this purpose. A tide correction was applied, based on the Oregon State University (OSU) tidal prediction software (OTPS) that is retrievable through MB-System. In general, there is a tide difference of less than 20 cm in the Black Sea. Further roll, pitch, heave and sound velocity corrections were not applied for the MSM15-1 data. Bathymetric data has been manually cleaned for existing artefacts with mbeditviz. NetCDF (GMT) grids of the product and the statistics were created using mbgrid. Quality assurance was furthermore proven by visual and statistical comparison of crossing survey-lines from different cruises throughout the Black Sea. No total propagated uncertainty (TPU) has been calculated to gather vertical or horizontal accuracy. The currently published bathymetric grid of the cruise has a resolution of 70 m. A higher resolution is, at least partly, achievable. The extended _sd -grid contains the standard deviation for each cell. All grids produced are retrievable through the PANGAEA database (www.pangaea.de). Chief Scientist: Antje Boetius (AWI) CR: http://doi.pangaea.de/10.2312/cr_msm15_1 CSR: http://www.bsh.de/aktdat/dod/fahrtergebnis/2010/20100150.htm Publications related to the cruise: https://www.pangaea.de/search?q=Campaign:MSM15/1 Bathymetry (EM1002) published under: https://doi.pangaea.de/10.1594/PANGAEA.738638 A special thanks goes to the watchkeeper during this cruise: S. Albrecht, Z. Erdem Another thanks goes to the student helper who helped to create this product: N. Brückner, S. Gaide, S. Oelfke