Navigable for boats, or small river-craft.--Webster.
This useful word has only recently been adopted in the English dictionaries.
The Seneca Indians say, they can walk four times a day from the boatable waters of the Allegany, to those of the Tioga.--Morse's Geography.
This word, says Dr. Webster, though of modern origin, is well formed according to the English analogies, like fordable, creditable, &c. The advantage of using it is obvious, as it expresses an important distinction in the capacity of water to bear vessels. Navigable is a term of which boatable is the species; and as the use of it saves a circumlocution, instead of being proscribed, it should be received as a real improvement.--Letter to J. Pickering on his Vocabulary, p. 6.
The objection to this word is, that it is a hybrid, composed of a Saxon noun and a Latin ending. It is like fordable, but not like creditable, which is all Latin. We would hardly use the word trustable.