Boucher, Labbé, and Clanet reply: Eric Firing gives an interesting comment on our Quick Study. We reported the observation, with a model robotic rowing boat, that being synchronized goes faster than being asynchronized. Our explanation of the difference was that in the synchronized configuration, the motion of the rowers with respect to the boat during the recovery stroke had a propulsive effect, but that effect was canceled out in the asynchronous case.
With further experiments on our model boat, we confirmed that effect as we observed that when the rowers were synchronized, the higher the mass of the rowers, the higher the speed of the boat. However, after further investigations and as Firing suggests, we think the phase shift between rowers might also affect the efficiency of oar propulsion. Our current study on oar propulsion will surely clarify that point.
