"Navigable" revisited...

I am sitting here with a copy of the Navigable Waterway 'Non-rule' Policy IN HAND, and I cannot give you a concrete definition of a navigable waterway. It can be very confusing and IS NOT black and white! I do, however, have a list of navigable waterways. You might try looking up State v. Kivett, 228 Ind. 629, 95 N.E.2d 148 (1950). This is supposedly a landmark decision to test for determining navigability.
In the absence of a contrary state boundary, the appropriate line of demarcation for a navigable waterway is the ordinary high water mark.
THe IN Supreme Court stated that the test for determining navigability is whether a waterway: was available and susceptible for navigation according ot the general rules of river transprtation at the time(1816) IN was admitted to the Union. It does not depend on whether it is now navigable. The true test seems to be the capacity of the stream, rather than the manner or extent of use. And the mere fact that the presence of sandbars or driftwood or stone or other objects, which at times render the stream unfit for transportation, does not destroy its actual capacity and sucseptibility for that use.
...ARE YOU CONFUSED YET???
In regard to the river bed, if the waterway was navigable on the date of statehood, title of the bed of the river passed to the state of IN and could not be ordinarily conveyed incident to the adjoining riparian property. ALSO, once a waterway is found to be navigable, it remains so, even if the waterway is no longer used for purposes of commercial navigation.

Thats the best I can do. If a waterway is considered navigable, one can wade, swim, fish, etc. BELOW the ordinary high water mark, which is the transition area between the bank and where vegetation, trees, etc. begin to grow, without permission from the adjacent property owner. Normally, it is a well defined line, usually where the vertical (or nearly so) bank meets the top of the horizontal bank.