Details from Carta nautica, Estensi Digital Library, Biblioteca Estense Universitaria, Modena. Permission pending from the Ministry of Cultural Heritage and Activities, Italy.

Scholars disagree over whether the charts taken to sea had decorative compass roses painted on them. Navigators did not need them, and captains may have been wary of paying for the extra expense of having the chartmakers add them. When decorative compass roses do appear on Atlantic charts, not only are they easily visible but they frame the geography of the ocean in a powerful visual way. On the oldest surviving Portuguese chart, the Carta nautica, (see plate 8), the anonymous chartmaker created two styles of roses: one for the central compass rose and another for the smaller sub-rose. The central rose  (see above, center) is larger than the sub-roses (see above, right and left) and it has sixteen points. The sub-roses are nearly identical: each has eight points, its triangular pointers are colored in red and black, and on top is a black, helmet-shape that points North. All of the sub-roses form a matching set.  While the central rose is distinctively different, its colors repeat those of the sub-roses, and its top piece is a more decorative version of the top pieces on the sub-roses. They form a matching set.