The lock is then filled with more water to raise the boat to its next level, or it is emptied to lower the boat ​ — depending on which is needed. What if former locks cannot be restored?
ثم يُملأ الهويس بمزيد من الماء لرفع المركب الى مستوى اعلى ،‏ او يفرَّغ من الماء حتى ينخفض المركب الى مستوى ادنى ،‏ حسبما يكون ضروريا .‏