- The waterway must be deep enough to allow the draft depth of the vessels using it;
- The waterway must be wide enough to allow passage for the beam width of the vessels using it;
- The waterway must be free of barriers to navigation such as waterfalls and rapids, or have a way around them (such as canal locks and boat lifts);
- The current of the waterway must be mild enough to allow vessels to make headway.
Canals are artificial waterways that are constructed to provide a new path of travel for vessels (as opposed to improving a natural waterway along its current course). At one time, canals were built mostly for small wooden barges drawn by horses or other draft animals. Today, major canals are built to allow passage of large ocean-going vessels (see Ship canal) to connect harbours with or create a shortcut between seas and existing waterways, such as the Kiel Canal between the North Sea and the Baltic Sea, which is the most heavily used canal worldwide.
- Great Lakes Waterway
- International waterway
- List of countries by waterways length
- List of waterways
- NoorderSoft Waterways Database
- Saint Lawrence Seaway
- Strait of Magellan
- World Rivers Day
Wikimedia Foundation. 2010.