Mappings of Potential Sailing Mobility during Antiquity: Research Data
Merchant sailing ships in Antiquity possessed very limited upwind capabilities and their sailing mobility was predominantly determined by variability of the wind. Mapping of potential sailing mobility in Antiquity has eluded researchers who have attempted to derive sailing abilities of ancient ships from averaged climatic wind data. A PhD study completed in 2022 at the University of Haifa, Department of Maritime Civilizations took a different approach using Data Science methods. The underlying premise was that (a) the variabilities typical to Mediterranean winds are the key drivers of sailing mobility especially when a sailing passage lies contrary to prevailing winds; (b) these variabilities can be resolved in a large modern meteorological data set at high spatiotemporal resolution but are lost in averaged climatic data sets; and (c) palaeoclimatological examination has shown that the wind patterns in the Mediterranean have not changed in the last 3000 years and more. Sailing passages are reconstructed throughout the data set using regatta weather-routing software. This reduces the meteorological data, which is in the order of billions of records, to millions of sailing records. These are further reduced by statistical methods to obtain metrics of potential sailing mobility and are published in the data sheets for both direct sailing passages and for breeze assisted coastal sailing. The ancient mariners' limits of reasonability are also modelled in the process of determining practical potential sailing mobility. The tools to produce additional data remain in place and active. Additional measures of potential sailing mobility produced since the original research have been added to the repository. Potential sailing mobility measures for the Red Sea have been added in Version 4 of the data repository. Sheets exist for both Roman single main square sail rigs and for Indian Ocean type vessels rigged with Lateen sails. This facilitates comparisons of practical windward sailing in the Red Sea environment.