This Idea is for a gadget suited for letting dolphins play tic-tac-
toe. Obviously it has to be waterproof and corrosion-proof (and
as biological-growth proof as possible --barnacles not allowed!).
If we want it to be playable most anyplace, then it needs to
Instead of simply floating
on the surface where wave action will
often prevent it from being stable, I'm going to suggest a two-
level gadget. Part of it consists of something foamy
like a surfboard) that floats on the surface, and part consists of
the main board that is suspended under the surface, perhaps 2
meters, attached to the float. If the suspenders are springy,
wave action can be muted, so that the game board stays
still, beneath the float.
I think it would be better if the game board was oriented
vertically instead of horizontally. It can have a horizontal
to which the suspenders are attached. The wider the
points, the more stable will be the game-board.
Also, I want a purely mechanical game-board, so that we don't
have to worry about such things as electronics getting wet. A
days of mulling this Idea over has led me to the following
First, the board may have significant thickness, and the back
of the board is featureless. Only the front side gets the
of the game-players.
Second, the board needs to be somewhat largish, say half a
on a side, because dolphins don't have fine manipulators like
fingers. They will have to interact with the game using their
Third, the pieces (Xs and Os) cannot be loose; they must be part
of the game-board. The ocean can be miles deep, and loose
pieces will inevitably eventually become lost pieces.
Fourth, the game pieces need to have significant textural
differences, not just coloration differences. While dolphin
is good, they use sonar as their primary sense when underwater.
So sonar needs to be able to tell the difference between an X
an O and a blank.
Before getting to the main construction of the game board,
consider an equilateral triangle, and the center-point inside
triangle. Imagine an axle going through that center-point. We
now consider the 3rd dimension, and a prism that has a triangle
top, a triangle on the bottom, and 3 square sides. One side has
embossed/colored X, another has an embossed/colored O, and
third side is blank. We want 9 of these, of course.
Now imagine one of our prisms with one of its flat triangles on
ground, rotating about the center-point of the triangle. We
like to easily rotate it 1/3 of a whole rotation, and then have it
naturally stop. One way to do this is "detents", kind-of like this
If the bottom of the prism has a few protrusions, and the ground
has equivalent dents, then while rotating there can be a gap
between them, and when the protrusions align with the dents
prism can fall a bit, and it takes some effort to get it moving
again. The amount of effort depends on the angles of the
protrusions and dents, how big they are, and how many there
The main game-board is simply a frame for holding the 9
able prisms in a 3x3 grid. I want the axles of the prisms to be
very near the
surface of the game-frame; this means the pieces stick out
the game frame by a fair amount. More about that in a bit.
Part of each piece will be "inside" the game frame, between its
surface and the back side. When this part is a pointy portion of
the prism, that is when we want detents to hold the prism from
The part a prism that is outside the surface of the game-frame
will be showing a flat face. Either side of that flat face can be
pushed, to cause the prism to rotate. An appropriate gentle
would rotate it just enough that it would stop when the detents
mesh again. Note we will need to keep water resistance in
when constructing this gadget. With a bit of distance between
flat face of the piece and the game-frame, this allows dolphin
snouts space for pushing one side of a piece far enough for a
precise 1/3 rotation.
The "blank" face of the prism should have a small X at one edge
and a small O at the other edge. If the O is pushed, then
would bring the face of the prism containing the large O into
view. Same way for the X.
For either the X face or the O face of the prism, there also
to be a small symbol at one side (X on the O face and O on the X
face), in order to make it easy to notice which side of the
face to push, to bring the blank face back into view.
Well, that should suffice as a good-enough description of the
gadget. Getting dolphins to actually learn and play tic-tac-toe
another thing altogether! Human divers could show-by-
would dolphins be interested? To Be Determined!
Addendum: On one side of the game-frame there could be a
large static X and on the other side there could be a large static
O. When divers show the dolphins how to play the game, one at
each side of the game-frame, that addition can help make it
obvious that X goes first, and players take turns, each working
with just one of the two symbols. The divers can switch places
to make it obvious that anyone can play either symbol.