We noted earlier how the orientation of a rei miro ship is vertical:

GD13 glyphs are raised upright as if standing on their front ends - not at all looking as if they were sailing on the sea.

We can now guess why - because at a cardinal point the canoe has to be turned around in order to be oriented in a new direction. The upraised position of the Rei glyphs is a signal (a symbol) to the reader that the ship is turning.

When we turn the glyph around into 'travelling position' we immediately can see that the front end (right) is higher than the stern (which is designed like a fish tail).