IMPERIAL NAVY
As expected, emblems and symbols that appear on IJN cups are the
following: anchors, ships, water, cherry blossoms, and the naval battle flag.
Examples
A rare cup, this one with a naval combat helmet.
The Army helmet has a star and the Navy helmet
has an anchor. These helmets are rarely found on
cups.
Here is a minor treasure: a naval fighter plane on a cup.
Most cups that have a plane are from Army units. There is a
fighter plane on one side and a naval anchor in the base.
The characters say, 'Tokushima Island, Navy Airborne Unit,
Completion Ceremony Commemorative, Showa 18 [1943],
May.' The bowl is white.
Very rare naval cup made for a
bugler.  The characters say,
'Yokosuka Naval Barracks, Bugler
Corps, Discharge Commemorative.'
I have included some close-ups of
the kanji so you can identify them if
they appear on one of your own
cups. They are a bit faded, sorry.
Yokosuka
Naval Barracks
Bugler Corps. (Shou-Shin-Gou-Hei)
Note that this term was for a bugler who gave signal on board ship
Also seen often on naval cups is the IJN
flag. Here you can see it on the left.
Another naval combat
helmet. Inscribed 'China
Incident, Navy.'
Kutani cup with anchor and some other object,
possibly a compass rose. (Thanks for the
suggestion, Mike!) Inscribed 'Yokosuka Naval
Barracks, Leaving the Barracks Commemorative,
Kawauchi'.
A rare Billeting
(Quartering) Unit cup.
Inscribed 'Navy, Billeting
Unit Commemorative'.