"compass charts" or "loxodromic charts" whereas modern French scholars prefer to call them just "nautical charts" to avoid any relationship with portolani.

Several definitions of portolan chart coexist in the literature. A narrow definition includes only medieval or, at the latest, early modern sea charts (i.e. those that primarily focus on sea basins and coastlines, leaving the depictions of inland areas with little or no content) that include a network of rhumb lines