Multibeam data (MBES) based on the KONGSBERG EM120 Multibeam echosounder was recorded during the RV MARIA S. MERIAN cruise MSM20/4 (WACOM). The cruise took place between 14.3.2012 and 7.4.2012 in the West Atlantic (Florida Strait, Caribbean). Being a part of the international program TRACES (Trans Atlantic Corel Ecosystem Studies) the main research goal of the cruise was the investigation of the occurrence and diversity of cold water corals (CWC), to compare these findings with information about coral ecosystems in other parts of the Atlantic. Using sampling equipment (CTD, box and gravity corer) as well as the Remotely Operating Vehicle (ROV) CHEROKEE (MARUM) physical and biological factors, which control the occurrence of CWCs, were further examined. Hydroacoustic equipment like the Kongsberg EM120, EM1002 multibeam echosounder (MBES) and the Parasound PS70 subbottom profiler (Teledyne ATLAS) were used to map research areas and to plan sampling stations. CI Citation: Paul Wintersteller (seafloor-imaging@marum.de) as responsible party for bathymetry raw data ingest and approval. Description of the data source: During the RV MARIA S MERIAN cruise MSM20/4 the ships hull-mounted KONGSBERG EM120 multibeam echosounder with a nominal sounding frequency of 12 kHz was utilized. Up to 191 individual are formed for each ping while the seafloor is detected using amplitude and phase information for each beam sounding. The beam spacing was equidistal and the maximum swath angle was set to 120°. Pitch and Yaw stabilizations were used. Multiple CTDs were taken during the cruise. Terefore Sound Velocity Profiles were calculated and applied to the multibeam data. In addition to the KONGSBERG EM120 the EM1002 was used in shallower water depths. For further information consult https://www.km.kongsberg.com/. Responsible person during this cruise / PI: Paul Wintersteller (seafloor-imaging@marum.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. CTD and XCTD measurements were done between or during the MBES surveys to receive sound velocity profiles (SVP), which were applied during the acquisition of the hydroacoustic data. NetCDF (GMT) grids of the edited data as well as statitics were created with mbgrid. The published bathymetric grid of the cruise MSM20/4 has a resolution of 20 m. Additionally grids containing data from the four different working areas (Transit Yucatan, West Florida, Yucatan and Bahamas), which have a resolution of 10 m, are additionally published. No total propagated uncertainty (TPU) has been calculated to gather vertical or horizontal accuracy. A higher resolution is, at least partly, achievable. The grid extended with _num represents a raster dataset with the statistical number of beams/depths taken into account to create the depth of the cell. 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: Dierk Hebbeln (dhebbeln@marum.de) CR: https://www.tib.eu/de/suchen/id/awi%3Adoi~10.2312%252Fcr_msm20_4/ CSR: https://www2.bsh.de/aktdat/dod/fahrtergebnis/2012/20120077.htm A special thanks goes to various wachkeepers during the cruise and the student assistance who helped with the product: Stefanie Gaide