Energy cost and efficiency of sculling a Venetian gondola.

Oxygen uptake was measured on four male subjects during sculling gondolas at constant speeds from approximately 1 to approximately 3 m.s-1. The number of scullers on board in the different trials was one, two or four. Tractional water resistance (drag, D, N) was also measured in the same range of speeds. Energy cost of locomotion per unit of distance (C, J.m-1), as calculated from the ratio of O2 uptake above resting to, increased with v according to a power function (C = 155.2.v1.67; r = 0.88). Also D could be described as a power function of the speed: D = 12.3.v2.21; r = 0.94). The overall efficiency of motion, as obtained from the ratio of D to C, increased with speed from 9.2% at 1.41 m.s-1 to 14.5% at 3.08 m.s-1. It is concluded that, in spite of this relatively low efficiency of motion, the gondola is a very economic means. Indeed, at low speeds (approximately 1 m.s-1), the absolute amount of energy for propelling a gondola is the same as that for waking on the level at the same speed for a subject of 70 kg body mass.