隨著船舶開始轉向，在轉向期間，船舶在水中滑行，會導致大量的水阻力不斷抵抗方向航，產生側向阻力。藉由改變側向阻力和方向航力之間的平衡，將前者減小到最小，才能將後者發揮到最大潛力，來實現向前航行。為達到最佳效果，首先必須將船的速度降低到等於或慢於死角的速度。隨著速度的降低，沿著船側的水流以及此時的側向阻力隨之減小，使舵力獲得最佳效果。船舶在狹水道和淺水中航行時，必須確保其舵效，才能獲得航行的安全。

As the ship starts to turn, during the turning period, the ship slides in the water, which will cause a large amount of water resistance to continuously resist the rudder, resulting in lateral resistance. By changing the balance between lateral resistance and rudder force, and reducing the former to a minimum, the latter can be used to its maximum potential to achieve forward sailing. In order to achieve the best results, the speed of the ship must first be reduced to be equal to or slower than the speed of the blind spot. As the speed decreases, the water flow along the side of the ship and the lateral resistance at this time are the smallest, so that the rudder force can be utilized to the greatest extent. When a ship navigates in narrow waterways and shallow waters, its rudder efficiency must be ensured in order to obtain the safety of navigation.