Processed conductivity–temperature–depth (CTD) and dissolved oxygen water-column profiles from ROV SuBastian dives during 2025 R/V Falkor (too) expedition FKt250712 in the Mar del Plata Canyon, SW Atlantic

This data set comprises downcast and upcast water-column profiles of temperature, salinity, pressure, depth, and dissolved oxygen (concentration and saturation) collected by sensors mounted on the remotely-operated vehicle (ROV) SuBastian during the 2025 R/V Falkor (too) expedition FKt250712. Measurements derive from a Sea-Bird SBE49 FastCAT CTD and an Aanderaa optode oxygen sensor logged continuously throughout each dive. Raw per-sensor streams were parsed, time-stamped to one-second resolution, merged onto a common time base by nearest-neighbor matching within a ±2 s tolerance, and resampled to a uniform 0.1 Hz grid (one sample every 10 s) using linear interpolation with edge gap-filling. Samples shallower than 50 m were removed to exclude surface and deck operations, and the remaining record for each dive was split into a descent (downcast) segment ending at the logged on-bottom time and an ascent (upcast) segment beginning at the logged off-bottom time. Profiles are provided in the ASCII Sea-Bird CNV format.