For the purposes of granting presumption of exposure to herbicide, the VA Compensation Division has stated that no ports, bays or harbors are considered Inland Water, regardless of what color they might have been. Even though several Regional Offices as well as the Board of Veterans Appeals has several times awarded presumptive exposure to herbicide (Agent Orange-dioxin) to a veteran who was clearly outside the confines of that definition, those rulings do not set precedent and apply only to the circumstances of that specific individual.
Yes, that is very inconsistent, illogical and seemingly a 'legal contradiction.' But VA states that each case is unique and associated rulings only apply to that specific veteran. This is a very strong target for a legally-based attack BUT FOR THE FACT that VA Law is not a part of the American legal system of the public courts. It is based on a set of rules and regulations that stand apart from common law as used in the public courtroom.
For a “Blue Water” ship to be considered to have served on “brown water,” the ship had to have actually passed an imaginary line drawn across the mouth of a river or canal and located itself (at least partly) within the geographical boundary of Vietnam.
Any of the many inlets along the shore, including the ports, bays and harbors, that are open to the sea for deep water vessels are not considered Inland Waterways under the definition of the Inland Waterways Project 211, 211_AOSHIPS.VBACO@va.gov, which is the office within the VA that releases a list of ships that are acknowledged to fall within the VA definition of ships having been on Inland Waters or ships that had crew that went ashore. In this latter instance, only those specific crew members that went ashore (and thus had "boots-on-ground") are granted the presumption of exposure, not the entire ship's crew.
I hope that helps you understand the current distinction that the VA is making in their definition of “Blue Water Navy.”