The efficiency of a boat's hull design can be judged by the magnitude of the rooster tail—larger rooster tails indicate less efficient designs. If a water skier is in tow, the skis also throw off a rooster tail.
The performance of a boat's hull can be determined by the size of the rooster tail—larger tails signify poorer designs. Likewise, water skiers' skis also produce a rooster tail when in tow.