(nautical) A deeper channel cut into the sea or river bed, to enable larger ships to pass through to a port.

(nautical) The farthest point above the mouth of a river that can be navigated by ships. This term can be somewhat subjective on many streams, as this point may vary greatly with the size of the ship being contemplated for navigation. On others it is quite objective, being caused by a waterfall, dam or lock.

plural of navigation channel

Practice of calculating one's position and velocity using radio signals transmitted from space satellites as reference.

(computing) A data structure used in artificial intelligence applications to aid agents in pathfinding through large spaces. It is a collection of two-dimensional convex polygons.

plural of navigation mesh

Used other than figuratively or idiomatically: see navigable, waters.

plural of navigation light

(nautical, aviation) one of two or more lights fitted to a ship or aircraft, which indicate position and direction taken, especially important at night. Internationally recognised colours are red on the port side, and green on the starboard side.

The principle in customary international law that ships flying the flag of a sovereign state shall not suffer interference from other states, unless when excepted by international law.