Groundtruthing example

Example of video observations over shaded relief bathymetry and corresponding seafloor photographs. The red dots on the map indicate observations of sediment (sand or mud), while blue dots indicate observations of hard ground (rock, boulder). The photograph taken at the hard ground observation (top) over a pinnacle shows an almost vertical rock wall. The photograph taken over a flat seafloor with a sediment observation (bottom) shows a seafloor covered in coarse sands.