Most of the distances represent the shortest navigable routes, but in some cases, longer routes, that take advantage of favorable currents, have been used.
The purposes of these to divert and control the water from the river, to harness its power and to provide a navigable route to the sea.
It provided a navigable route connected by canals to the Delaware River starting in the late 18th century.
The government offered £20,000 to anyone that could find a navigable route but a private expedition by Moor and Smith in 1746-47 likewise returned empty-handed.
It provides a navigable route along its length without many of the hazards of travel on the open sea.
While this is marked as a tarmac road on most modern maps including the current Michelin series it has not existed as a navigable route for some decades.
There is no naturally navigable route between the two cities, resulting in several schemes.
This navigable route became known as the Victoria Channel.
Day beacons may also mark smaller navigable routes in their entirety.
An eight-man organising committee was established to create a suitably challenging but navigable route.