locks
Gate is the name given to the lower barrier of a canal lock. A Canal lock is used to lower and raise the water to move boats along a waterway.
I think you are referring to locks;used to lower and raise water levels for ship transportation.
Narrow boats.
It is a canal.
a canal
The Chemung Canal was very similar to the Erie Canal. It connected the Finger Lakes region of New York with the Susquehanna River. Both canals used barges or packet boats.
It transports boats from the Forth and Clyde canal to the Union canal and vice versa
The Grand Canal is the largest canal in the world. When the river was originally created it was used for supply boats and trade boats to go between the northern nations and the southern nations.
I'd say it's a canal.
A water channel, man-made and used for navigation
A series of Locks and Dams raise and lower water levels along a river to allow boats to pass through uneven water terrain.