Published online by Cambridge University Press: 29 March 2006
A series of decelerative swimming motions of a dolphin were recorded underwater showing that the animal decelerated more rapidly than could be accounted for by frictional drag. The theory of swimming slender bodies was used to calculate the mean thrust on the dolphin produced by the observed motions. It is shown that the dolphin is decelerating by producing a swimming thrust opposite to the direction of swimming.