A multi-scale process-based substrate map of the Belgian Part of the North Sea. A proxy of the surficial sediment type is mapped using automated seafloor classification using derivates of very-high resolution multibeam bathymetry from Flemish Hydrography ( https://www.agentschapmdk.be/en/flemish-hydrography), informed by sediment dynamics and geological processes. The mapping was steered towards a Folk classification (Folk, 1954) representing a maximum of fifteen major textural groups defined on ratios of silt-clay (< 63 µm), sand (63 µm to 2 mm) and gravel (> 2 mm) percentages. The original classification (15 classes) was merged into 6 classes and 4 classes, the latter to align with the requirements of Europe’s Marine Strategy Framework Directive.