A while back I referred to the bwnazmzw juncture as an "out-of-focus
quadripoint": an area where four countries met, almost certainly in two
tripoints, but in an ill-defined way. My various readings around EEZ
boundaries has turned up several more of these. The list is as follows:

BWNAZMZW
The original. Decomposes into either bwnazw+nazmzw or bwzmzw+bwnazm,
depending on where the confluence of the Chobe River (bwna) and Zambezi
River (nazm, zmzw) lies relative to the line of the bwzw border markers.

FRGBNLUS
The maritime border between Saint Martin and Sint Maarten (frnl) has not
been agreed. Its western extension, based on the principle of
equidistance, depends critically on the location of the western terminus
of the land border. This is usually shown terminating on the SW coast of
the island, which would propagate the equidistance line in a SW
direction. However, many maps of potential maritime boundaries (Jane's,
Prescott) show this boundary heading NW. The SW extension of the frnl
boundary hits the Puerto Rican equidistance line, creating tripoints
frnlus+frgbus; the NW extension hits the agreed boundary between Saint
Martin & Anguilla, creating tripoints frgbnl+gbnlus.

BGROTRUA
In the Black Sea, Turkey has agreed boundaries with Bulgaria and
Ukraine. Romania's borders with both Ukraine and Bulgaria are not
determined. The detailed line of roua will determine whether bgrotrua
decomposes into rotrua+bgrotr or bgtrua+bgroua.

CYEGGRTR
On a straight principle of equidistance, Greece has an EEZ boundary with
Cyprus, intruding between Turkish and Egyptian waters. However, none of
these borders are determined by treaty. The run of grtr is particularly
sensitive to how much weight is given to the Greek Megisti islands, 1nm
off the coast of Turkey - full equidistance would be inequitable for
Turkey, since the islands would generate 5000sq nm of EEZ for Greece. If
the Megisti islands were not given full weight, this would shift grtr
westwards, potentially converting cygrtr+cyeggr to cyegtr+eggrtr.

JPKPKRRU
The Liancourt Rocks are disputed by South Korea and Japan. The northern
end of the disputed area adjoins the convergence of kpru&kpkr. So if
South Korea owns the rocks, it has a border with Russia, and the
quadriarea decomposes into kpkrru+jpkrru. If Japan owns the rocks it has
a border with North Korea, giving jpkpkr+jpkpru.

COCRNIPA
Nicaragua and Colombia dispute ownership of the San Andres y Providencia
archipelago in the Caribbean. So at its southern end coni may fall west
or east of the line crpa. If Colombia owns the islands, it will have a
border with Costa Rica, and the tripoints are cocrpa+cocrni. If
Nicaragua owns the islands, this changes to conipa+crnipa.

(CO)GBHNJM(NI)
At the northern end of the disputed coni line, Honduras has become
involved in the dispute by agreeing a border with Colombia, cutting
across the area Nicaragua claims. In this agreement, Colombia has not
taken full equidistance from the Seranilla Bank. If this southerly cohn
line stands, it allows Honduras an equidistance border with Jamaica,
separating the British Cayman Islands from Columbian waters. The
tripoints are therefore gbhnjm+cohnjm. However, if the Nicaraguan claim
stands, Nicaragua could try for full equidistance from Seranilla,
thereby pushing its EEZ north between Honduras and Jamaica to form a
border with the Caymans. This would give tripoints gbhnni+gbjmni.

If anyone else finds this at all interesting, I can upload some sketch
maps to better show what's going on.

Grant