Being streamline means having a position in the water that creates as less drag/resistance as possible.
Brent S. Rushall said :
« It is important to consider resistance in terms of swimming performance. If resistance can be minimized, then the propulsive effects of a swimmer’s efforts will be maximized. »[Rushall B. and all 1994] (Part IV – Resistive Force)
There is 3 differents kind of resistance that a swimmer as to face [M. Toussaint and Peter J. Beek, 1992]:
- The pressure drag
- The wave-making resistance
- The frictional drag