Fig. 6. Measurement of in vivo drag in a coasting fish at Re_max=1050. The inertial drag coefficient for this fish (L=25 mm) was calculated from measurements of body mass and surface area and (A) the inverse of instantaneous speed measurements during coasting (filled circles). The drag coefficient (C_inert=0.05) was found from a least-squares linear fit (red line) to the data, which (B) provided a prediction (red line) for the measured changes in the cranial position (filled circles).