The Multi-corer (MUC) was used during the RV SONNE cruise SO304 in 2024 to retrieve undisturbed sediment cores of up to 60 cm in length, preserving the fluffy seabed surface, sediment–water interface, and overlying bottom water. Each deployment recovered a set of eight tubes (60 cm length, 8 cm inner diameter), four of which were transparent standard PVC liners. Five MUC cores (GeoB25824-2, GeoB25824-7, GeoB25825-2, GeoB25828-4, and GeoB25829-2) were selected for grain-size analysis. All cores were collected within the 'Swatch of No ground (SoNG)' submarine canyon. GeoB25824-2 and GeoB25824-7 were sampled before and after mooring deployment during the cruise, respectively. The water depths at the five stations were 588, 586, 323, 588, and 719 m, and the recovered core lengths were 38, 33, 42, 53, and 50 cm, respectively. The cores were subsampled at 1 cm intervals. Grain-size analyses were conducted at the MARUM – Center for Marine Environmental Sciences, University of Bremen, Germany. Grain size was measured using a Beckman Coulter Laser Diffraction Particle Size Analyzer LS 13320. Prior to measurement, samples were treated with Na₄P₂O₇·10H₂O and boiled to disperse aggregates.