16th International Symposium on Boat & Ship Archaeology

52 16 th International Symposium on Boat & Ship Archaeology David Gal 1 , Hadas Saaroni 2 & Deborah Cvikel 1 1 Department of Maritime Civilizations and the Leon Recanati Institute for Maritime Studies, University of Haifa, Haifa, Israel 2 Department of Geography and the Human Environment, Porter School of the Environment and Earth Sciences, Tel Aviv University, Tel Aviv, Israel Method for mapping potential ancient sailing mobility: new meaning to the term ‘favourable winds’ A new method has been developed for measuring potential sailing mobility of loose footed single square sail merchant ships in the ancient Mediterranean, with the objective of mapping potential sailing mobility in the central and eastern Mediterranean basins. This method is applicable to both direct open water sailing passages and to coastal-breeze driven sailing. Many previous quantitative works have evaluated sailing passages using averaged wind as input, losing information on the intra- and inter-diurnal variability of the winds in the Mediterranean. Their sole measure of mobility has been a representation of sailing speed on direct crossings. Moreover, these Mediterranean studies have not considered the dif- ference between technological and practical mobility, which is driven by human factors, for instance, the choice of whether to sail or to wait for better conditions. The proposed method uses meteorological resources at high spatial and temporal resolutions, with the premise of exploiting the recurring wind varia- bilities and patterns which are key to mobility, especially on routes contrary to the prevailing winds. The underlying methodology converts meteorological ‘big data’ to ‘big data’ of hundreds of thousands of simulated sailing passages. The latter providing for statistical analysis of potential sailing mobility. Inclusion of criteria-based human factors – e.g. the preferences of the mariners of the period, provides realistic measures of mobility, representing not only sailing speed, but also waiting time and the probability of conducting feasible passages at given times of the year. Sailings of the replica ship Ma‘agan Mikhael II supported the development of the method with valuable input of ship performance. One of the aims of the study is to publish a mapping of potential sailing mo- bility in support of studies of Mediterranean maritime space. This new method provides deeper insight into potential sailing mobility and the understanding of seafaring in the Mediterranean.