Bathymetric dataset for full-ocean-depth EM124 mapping of the Challenger Deep by R/V Hakuho-maru

This dataset contains raw, processed, and gridded bathymetric data acquired with a Kongsberg EM124 multibeam echosounder aboard R/V Hakuho-maru during cruise KH-23-9 in the Challenger Deep on 30 November 2023. It includes raw Kongsberg .kmall acquisition files; comma-delimited sounding point files recomputed and manually edited in CARIS HIPS; a vessel-configuration file containing the sensor geometry, offsets, mounting parameters, and waterline information used in processing; and the shell script used to generate the grids. The dataset also includes 20 GMT netCDF-4 bathymetric grids produced from accepted soundings using five seawater sound-velocity profiles and four grid spacings (50, 100, 200, and 500 m). Point files contain latitude, longitude, positive-down acoustic depth, edit status, and ancillary CARIS fields. Grid coordinates are longitude and latitude referenced to WGS-84, and grid z values are expressed in metres as negative values below the survey sea surface. The fixed grid domain is 141-144E and 10-13N; cells without adequate data support are stored as missing values.