The Size and Shape
Looking at the portolan chart as a whole, a viewer is first impressed by its very large size, almost two and a half by four feet.
This portolan chart is made on two skins, equal in size (about two by two and a half feet each) joined in the center to form the large rectangular map.
Was a chart of this size and beauty meant to be used at sea? Possibly and possibly not. Does beauty belie usefulness? The holes along the eastern edge appear to indicate that it was attached to a wooden roller, and wormholes running through parts of the portolan chart indicate that it was rolled for at least some of its existence, either for storage or while at sea.