Natural subtidal hard substrate communities are vulnerable and fragile biotopes. Their spatiotemporal characterization should thus focus on non- or minimally invasive sampling gears such as underwater imagery. MARECO has extensive experience deploying towed underwater imagery systems, consecutive data processing and analysis. The application of remote sensing methods prevails over conventional sampling methods (e.g. grabs), providing a refined understanding of benthic communities at various spatial scales. Gathered knowledge serves as a foundation for establishing baselines and conducting comprehensive assessments in several national monitoring programs. Currently, our team is developing semi-automated annotation methods to augment data processing capacity and time efficiency.