Fig. 4. Sighting distances (m) in all species as a function of wavelength (nm) and depth (m). The sighting distance is color coded in the figures from long distances as red to short distances as blue (see color bar). The following viewing angles (from top to bottom) are displayed: from directly above (180°), diagonally above (150°), horizontal (90°), diagonally below (30°) and directly below (0°).