Multibeam Echosounder (MBES) bathymetry and backscatter data were acquired in the UK-1 exploration area of the Clarion-Clipperton Zone (CCZ), Pacific Ocean, using the Autonomous Underwater Vehicle (AUV) Autosub5-mounted Norbit WBMS-bathy MBES during RRS James Cook Cruise JC257 between 16/02/2024 and 09/03/2024. These datasets were collected to investigate local-scale seafloor morphology and to improve understanding of biodiversity patterns and benthic habitat distribution within the CCZ, by scientists from the National Oceanography Centre, Southampton, UK as part of the NERC-funded Seabed Mining And Resilience To EXperimental impact (SMARTEX). The AUV was used to map in high resolution the 0, 1, 16, 30 and 100 km sites. Bathymetric data were processed using Quality Positioning Services (QPS) Qimera 2.7.6, while backscatter data were subsequently processed using QPS FMGT 7.11.2. Tidal corrections were derived at the Long Mooring 1 site using the TMD toolbox, based on the TPXO global tidal inversion model developed at Oregon State University (OSU), and applied to the dataset. CTD-derived sound velocity profiles (SVPs) were then used to further refine the acoustic corrections. Semi-automatic and manual cleaning procedures were carried out to remove erroneous soundings, particularly along the outer swath edges. The 0–1 km site was surveyed during missions AS5M084 and AS5M085; the latter was spatially adjusted through the identification of common seafloor features. Sites at 16 and 30 km were surveyed during mission AS5M089. The 100 km site was mapped during missions AS5M093, AS5M094, and AS5M096, with AS5M093 used as a spatial reference to align the subsequent surveys based on shared geomorphological features. For each site, bathymetric grids were generated at 1, 2, and 5 m resolution, in WGS84 UTM Zone 11N projection, with interpolation applied where necessary to fill gaps between survey lines. Processed .gsf files were then exported to QPS FMGT to produce backscatter mosaics at 0.20 m resolution. Both backscatter and bathymetry data are supplied in .xyz format. Additionally, bathymetry are supplied in ESRI ASCII Raster format, and backscatter as GeoTIFF files.