Below, I quote in English translation from the Political Constitution of the
United Mexican States (as amended through June 26, 2003), which clarifies
several things that we've been wondering about Mexican state boundaries and the
question of federal/state sovereignty over the waters, etc.
____________________

ARTICLE 42:
The national territory comprehends:
I. That of the integral parts of the federation [defined in Article 43 below];
II. That of the islands, including the reefs and keys in the adjacent seas;
III. That of the Islands of Guadalupe and of Revillagigedo situated in the
Pacific Ocean;
IV. The continental shelf and the submarine pedestals of the islands, keys and
reefs;
V. The waters of the territorial seas in the extent and terms that the
international law fixes and the interior maritime [waters].
VI. The space situated above the national territory, with the extent and
modalities that the appropriate international law establishes.

ARTICLE 43:
The integral parts of the federation are the states of [names of the 31 states]
and the Federal District.

ARTICLE 44:
The City of Mexico is the Federal District, seat of the powers of the Union and
capital of the United Mexican States. It is composed of the territory that it
currently has and in case that the federal powers are transferred to another
place, it shall be erected into the State of the Valley of Mexico [el Estado del
Valle de México] with the boundaries and extent that the general Congress
assigns it.

ARTICLE 45:
The states of the federation keep the extent and boundaries that they have had
until today [February 5, 1917], whenever there is no difficulty as regards
these.

ARTICLE 46:
The states can adjust between themselves, by friendly agreements, their
respective boundaries; but these adjustments do not take effect without the
approval of the Congress of the Union.

ARTICLE 47:
The State of Nayarit will have the territorial extent and boundaries that
comprehend currently the Territory of Tepic. [This clarification was probably
thought necessary because the name was changed upon admission to statehood.]

ARTICLE 48:
The islands, the keys and the reefs of the adjacent seas that pertain to the
national territory, the continental shelf, the submarine pedestals of the
islands, of the keys and reefs, the territorial seas, the interior maritime
waters and the space situated above the national territory, depend directly from
the government of the federation, with exception of those islands over which
until this date [February 5, 1917] the states have exerted jurisdiction.
____________________

So to summarize:

The 31 states and the Federal District are "integral parts of the federation,"
and they get to keep their historic boundaries (from long before some bureaucrat
dreamed up the ZoFeMaT). Islands (except for those grandfathered in Article
48), keys, reefs, sea bottoms, territorial seas, interior maritime waters, and
space are classified differently from the states and are specifically described
as direct dependencies of the federal government.

Therefore, I would conclude that the constitutional boundary between coastal
states and the federally dependent wet places is the edge of the water. If
it's on the continent or one of the grandfathered islands (more on which below),
it's part of a state. If it's in the saltwater (even interior bays of the sea),
it's federal.

Whether the boundary should be the high- or low-tide mark would be speculation,
but I suspect that it would be the high tide. After all, the wave-swept beach
is part of the sea bed, at least one or two times per day. Perhaps this is why
the bureaucrats who dreamed up the ZoFeMaT measured this strip of federal public
domain from the high-tide line.

In light of all of this, I conclude that the ZoFeMaT is owned by the federal
government as landowner, and it is subject to the exclusive management of the
feds, but that the part of it that is dry ground or freshwater riverbed is part
of the territory of the respective states.

Lastly, about those grandfathered islands: Isla Guadalupe is about 165 miles
out in the Pacific Ocean, and the Islas Revillagigedo (Isla San Benedicto, Isla
Socorro, Isla Roca Partida, and Isla Clarión) are scattered from nearly 300 to
nearly 500 miles from land, also in the Pacific. Guadalupe belongs historically
to Baja California, while the Revillagigedos belong to Colima. Other Mexican
islands that are grandfathered under Article 48 are the obvious ones much nearer
the coasts.

Lowell G. McManus
Leesville, Louisiana, USA