Multiscale benthic images collected by Autonomous Underwater Vehicle during expedition JC257 in the UK-1 area of the Clarion-Clipperton Zone, Pacific Ocean, 2024.

A collection of 52,771 benthic still images was obtained using a downward-looking camera mounted on the UK Autosub5 Autonomous Underwater Vehicle (AUV), deployed from RRS James Cook during cruise JC257 in the abyssal plain (~4130 m depth) of the UK-1 exploration area of the Clarion-Clipperton Zone, Pacific Ocean, in 2024. During mission AS5M094, the AUV was programmed to replicate parallel 1-to-2 km long transect lines in four sites spaced by an array of scales, located 0, 15, 30, 100 km South from the northern border of the UK-1 exploration area. The Grasshopper2 GS2-GE-50S5C camera mounted on the AUV collected vertically orientated still images at a target altitude of 3 m above the seabed, with one image being captured per second. These images were colour-corrected to enhance visual fidelity and converted from original 8-bit RAW to JPG images. The image set includes images collected above 1.6 m and below 3 m altitude, which was corrected for the lever-arm corrected AUV pitch. The data were collected by scientists from the National Oceanography Centre, Southampton, UK as part of the NERC-funded Seabed Mining And Resilience To EXperimental impact (SMARTEX) project (NE/T003537/1).