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  • Navigation before and during the expedition

Navigation before and during the expedition

Institute of Naval History and Culture

Spanish Navy


The ships were solid and manoeuvrable, but due to their small size and the fact that they were made of wood, they were significantly weakened by the force of the elements they encountered, primarily the swell. There were two main types: the nao or carrack, which was larger and therefore had more sails, largely for cargo; and the caravel,more delicate and lighter, for exploration and carrying news and smaller cargo.

They used two types of sails: square, to take more advantage of favourable winds, those blowing in the direction in which the ship wassailing; and lateen, capable of sailing a bit against the wind. To move around when there was no wind, especially along the coast in order toharbour (anchor) or leave port, they used small boats, the largest of which was called a batel (dinghy). Its main function was loading and unloading, for as the ports had no other docks than small piers, wherethey had anything, the ships were always anchored.

To perform maintenance work on the ships’ hulls, essentially repairs, they simply beached them.

The majority of the crew lacked any private space whatsoever, and they slept where they could. Only the top officers – the captain; the chief navigation officer; the master, who was essentially the commander; and the pilot, who determined the ship’s position, the course to follow, and how the sails were used – had private quarters.


Any sailor of the time, like any minimally educated person, knew that the Earth is round, that the skies rotate (apparently) around it, and that the axis of rotation, which runs through it, points toward the Pole Star, thus indicating what we call North. Additionally, they understoodthat, because of this rotation, halfway through their daily journey, celestial bodies reach their maximum height when they are in a southerly direction (or northerly if the observer is far enough south). This enabled them to have a fairly good idea of the direction in which they were moving.

In addition, they knew that the angle above the horizon of both the Sun and the Pole Star, which they measured with an astrolabe or a quadrant, and a ballastella, respectively, indicates the latitude of the observer using simple calculations. With the addition of the compass, which was used in the West from the Late Middle Ages, and a rudimentary measurement of speed over the water using hourglasses,they could calculate the longitude of the route followed with some precision.

Cartography had made enormous advances in the previous two centuries, the positions of all the coastlines of the most heavily travelled seas being established quite accurately. However, maps were highly inaccurate for the lesser known ones, and non-existent forlarge portions of the Earth. The most significant gap in knowledge wasthe size of the Earth’s sphere, which many believed to be smaller than it actually was. As a result, it was debated whether the Indian Ocean was the sea that laps the shores of the New World (America), and some thought that the Moluccas were relatively close to the western coasts of the South Sea (Pacific Ocean), recently discovered by land from what is now Panama.

In other words, they knew with some accuracy where they were and what direction they had to follow to get to a given point on the surface of the globe. Naturally, errors could be considerable depending on how overcast the skies were (clouds prevented them from making their observations of the celestial bodies), errors in the measurements made with their instruments, and the force and direction of the currents, which could only be detected near the coast.


The diet was primarily based on dry or desiccated foods, such as legumes and rice, and salt fish or meat, or long-lasting items such as garlic, double-baked bread (biscuits) and oil. Rations were distributed once a day to sailors, divided into messes, each one of which cooked their own food. Rather than water, whenever they could, they drank wine, as it was much safer than the former when it had been stored for some time. The main problem they faced was a lack of vitamins due to limited access to fresh food on longer sailings.


The ships, packed spaces by definition, lacked even minimal sanitary facilities.
Waste of all kinds was removed by being sent overboard into the sea, and that is how the crew members relieved themselves, assisted to some extent by simple hanging seats. In the holds, infestations of insects and even rodents were unavoidable. On long sailings, the most fearsome illness, caused by avitaminosis, the result of the lack of fresh food, was scurvy.