LaRS is the largest and most diverse panoptic maritime obstacle detection dataset. Highlights: Diverse scenes from manual capture, public online videos and existing datasets USV-centric point of view 4000+ manually per-pixel labelled frames: 3 stuff categories and 8 thing (dynamic obstacles) categories 20 scene-level attributes (e.g. illumination, reflections, conditions) Temporal context for each annotated frame (9 preceding frames, total: 40k frames)