The multibeam echo sounder Kongsberg EM122 was recording bathymetric and backscatter data from 25.01.2023 (07:21 UTC) to the 20.02.2023 (15:55 UTC) outside EEZs during the transit from Mindelo (Cabo Verde) to Punta Arenas (Chile). It operates with an acoustic frequency of about 12 kHz and has a beam opening of 2° x 2°. During MSM114/2 the fan opening angle was set between 110°- 120° in dependency of the backscattering characteristics of the seabed resulting in a swath width of about 15 km in 5,000 m water depth. The dual-swath mode was used, resulting in up to 2 x 288 beams per ping. The raw and unprocessed bathymetric and backscatter data is stored in Kongsberg format (.all) each containing up to 30 min of data. The therein included time, motion and position data (WGS84, geographic) was measured by the Kongsberg Seapath system on board. During the acquisition the echo sounder was monitored as well as settings and filter adjusted according to the environment. Additionally, a small survey in the South Atlantic Ocean was performed on the 13.02.2023 south of the Cruzeiro do Sul Rift. A total of 45 CTD (conductivity, temperature, depth) stations were conducted during the cruise. Ten of them were imported into the MBES acquisition software SIS for improving the quality of the depth measurements. Two of them were deep-sea CTDs down to 4,000 m depth (31.01., 13.02.) and the other until 500 m respectively (26.01., 09.02., 11.02., 12.02., 13.02., 15.02., 16.02., 17.02.). The shallow SVPs (sound velocity profiles) were imported into the software "Sound Speed Manager" developed by NOAA Coast Survey and UNH CCOM/JHC and extended using the "World Ocean Atlas 2009" (WOA09) data base from NOAA (Levitius, 2013). When no measured SVP was available, SVPs were extracted from WOA09. This was done partially automatic once per hour. The SVP data is not part of this submission but can be extracted from the .all files.

These data should not be used for navigational purposes