What is an Oceanic Nautical Rutter in the Renaissance Really?

The straightforward answer would be: it is the technical document that details how to navigate from point A to point B. However, this statement does not draw enough attention to the complexity of nautical rutters. To explain how to navigate from A to B, many other issues have to be dealt with.

Information on winds, currents, tides, shallows, weather conditions, measurements on the declination of the magnetic needle and stories about what happened to other navigators were generally included in rutters. Nautical rutters were also used along with nautical cartography. If nautical charts used the data from nautical rutters to be built, pilots also used nautical charts alongside nautical rutters when sailing. Many rutters are also lively testimonies to the uneasiness caused by the globalizing 16th century development of long Oceanic voyages. In this sense, there are still too many unanswered questions regarding nautical rutters in the Iberian Renaissance.

In many instances rutters were composed by pilots, but were they written during the voyages? Several early 16th-century Iberian nautical rutters suggest that. Nevertheless, as soon as manuscript and printed compilations of rutters circulated, it becomes clear that there were standardized versions of rutters and that some of them were not written on board. In those cases, it is possible that pilots composed rutters on land after returning. Which were the criteria for the writing of those rutters and how could their scientific accuracy be ensured? Were there standard nautical rutters for certain routes, as happened with cartographical models, namely the Portuguese “Padrão Real” or the Spanish “Padrón Real”? How was Iberian nautical knowledge influenced by other maritime traditions, such as the Islamic and others? And finally, what were the critical stages of the knowledge transmission process for the French, the English and the Dutch, who all used Iberian nautical knowledge to start their overseas expansions?

The answer to these interrogations is still to be provided by a study of Iberian nautical rutters, a declared goal of the RUTTER project. However, in the process of answering these main questions, it is inevitable to be struck by the true richness of rutters and their impact on Renaissance science, society and culture. [Nuno Vila-Santa]