Overview

Until the advent of modern navigational tools in the sixteenth century, mariners had since ancient times used similar methods of navigating, largely by instinct. Even as late as the earliest voyages to the New World by Spanish and Portuguese explorers, mariners who embarked on voyages across open waters, out of the sight of land, could primarily only navigate by keeping a daily record of the general distances and directions they traveled, surrounding currents, wind patterns, hazards, and sightings of land. These journals, or ship logs, were used to notice "landmarks" at sea and retrace one's path back to their port of origin. Though pin-point navigation from these journals was difficult, the body of information collected over numerous voyages was...