Fig. 6. Relationship between measured speed (black line) and theoretical terminal speeds, assuming a total body density of 1043 kg m^-3 (red line) and 1015 kg m^-3 (blue line), during descent phases of dives for (A) weighted (July 5, 2005) and (B) unweighted (July 7, 2005) conditions. Depth, swaying acceleration and pitch (i.e. angle between long axis of seal's body and water surface, with positive values indicating ascent and negative descent) are also shown. Swimming behavior is categorized as prolonged glide (white horizontal bar) and stroke-and-glide swimming (grey horizontal bar) (see `Results' for categorization). Arrows indicate the first peaks of measured speed during prolonged glides.