The hydroacoustic surveys carried out during MARIA S. MERIAN cruise MSM86 were aimed to acquire detailed information of the areas of interest (Boyd Seamount; Logi Ridge; Vesteris; Vestnesa Ridge) with respect to backscatter and bathymetry. During MARIA S. MERIAN cruise MSM86, the Kongsberg EM 122 multibeam echosounder was operating almost continuously. Hydroacoustic surveys were usually conducted with a vessel speed of maximum 6 kn, while for some few sub-bottom profiles, a reduced speed of about 4 kn was applied. During transits the vessel speed was increased to 8-12 kn, depending on weather conditions. Sound velocity profiles were uploaded into the recording system online. Data has been processed according to the MB-System standard processing sequence.