The Syrians had to fight their way across Israeli fortifications and anti-tank ditches on the Golan Heights in 1973, and suffering very heavy losses from hull-down, dug-in Israeli tanks.
Pivoting on a pin inside the hull, it swings down to provide ballast and resistance against sideways motion of the boat caused by the wind blowing from one side.
它围绕船底的一个钉子旋转，放下时提供压载力，以抵抗由于单侧风导致的船只侧向摆动。
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Finally, some historic craft have leeboards instead of centerboards; these boards, mounted outside the hull on both sides, can be pivoted down like a centerboard to resist leeward motion.