All vessels. This is Avonport. Navigational warnings. There are pipelaying operations near gas leakage. 各船请注意,航行警告,在气体泄露处附近有管道敷设作业。
Sophisticated instruments which were to make possible the European voyages of discovery, such as the astrolabe , the quadrant, and good navigational maps, were also developed by Muslims. 复杂的仪器使得欧洲人得以进行海上探险,例如星盘、象限仪及好的航海图都是由穆斯林所发明的。
Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. The field of navigation includes four general categories: land navigation, marine navigation, aeronautic navigation, and space navigation.