Advantage of a lead swimmer in drafting
  We present results from model tests to investigate the effect of drafting in swimming, in particular for the lead swimmer. The drag for scaled-model passive swimmers was determined accurately at Froude numbers comparable to conditions for actual human swimmers. Several positions of a draft swimmer at different separations behind and alongside the lead swimmer were investigated. It was found that a lead swimmer can experience an advantage from a draft swimmer. Several other positions of the draft swimmer relative to the frontal wave generated by the lead swimmer were also considered. These results indicate favourable and undesirable positions during passing. 
J. Westerweel, K. Aslan, P. Pennings, B. Yilmaz
physics.flu-dyn