Fig. 6. Data (from Table 2) showing results of fluid mathematical modeling for whales of varying body length foraging at speeds of 4 km h^–1 (solid symbols) or 6 km h^–1 (open symbols). Pressure differential values were derived from four equations: Bernoulli (circle), two formulations of Hagen–Poiseuille (triangle, square) and Navier–Stokes (diamond). Calculations for L_b=5 m are not included here, as these were based on extrapolated morphometric data. For comparison, there was a mean 500 Pa pressure drop, measured via transducer, in the flow tank testing of the 1/15 scale physical model (33 cm head length; equivalent of L_b 1 m).