Fig. 5. Hydrodynamic forces on the body of a crab using the terrestrial (open circles) and aquatic (filled circles) postures at 0° angle of attack. Each data point represents the mean of five trials for an individual crab, and values are means ± 1 S.D. Reynolds numbers (based on maximum lateral width of a crab) range from 2.5x10⁴ to 2.0x10⁵. Drag force (A) was significantly different for the two postures at all velocities except 0.15ms^-1. Lift force (B) was not significantly different for the two postures. Arrows indicate the mean slow and mean fast punting speeds.