unnavigable

• unnavigatable

From un- +‎ navigable.

unnavigable (comparative more unnavigable, superlative most unnavigable)

1. Not navigable: difficult or impossible to navigate.

   Synonym: innavigable

   Antonym: navigable

   Near-synonym: impassible

   unnavigable website

   1. (nautical, of waters) Impossible to sail through; impassible to watercraft, unusable as a waterway (for example, too shallow).
      • 1950 May, Timothy H. Cobb, “The Tanganyika Railway”, in Railway Magazine, page 298:

        A road journey of 70 miles past unnavigable rapids leads to Juba, from which it is seven days' steaming down river through to Kosti, on the Sudan Railways.

      • 1996 January, “Southern Tibet”, in Gyurme Dorje, editor, Tibet Handbook: with Bhutan‎^[1], Passport Books, →ISBN, →LCCN, →OCLC, page 288, column 1:

        Nang county is the name given to the present administrative division of E Dakpo, the principal gateway to the sacred mountain of Tsari, and the region through which the Brahmaputra River cuts its way through an unnavigable 33 km horse-shoe gorge as it flows towards Longpo and Kongpo.

      • 2007, Graham Robb, “Chapter 1: The Undiscovered Continent”, in The Discovery of France: A Historical Geography, W.W. Norton and Company, →ISBN, page 21:

        The vast plateau of the Massif Central was still the fortress it had been when the Arverni tribes held out against the Romans. Its rivers were unnavigable and its links to the rest of France practically non-existent.

   2. (of a path, trail, or route) That is totally impassible: cannot be used for any reason.

      The trail was unnavigable since the flood washed it away.