The stated navigability limits are not a fixed limit. They are approximate recommendations for plastic canoes with a moderately experienced crew who can find a suitable stream even in lower water levels. The actual limit is always individual and depends on the type of boat, the experience of the paddler and the willingness to occasionally get out of the boat and drag it through shallower sections. Experienced paddlers often navigate rivers even in lower water levels below the navigability limit, while rafts, fiberglass boats or novice paddlers often need more water.