Measuring potential coastal sailing mobility with the loose-footed square sail

Measures of potential sailing mobility are essential for understanding the functioning of ancient maritime links. This requires measuring potential sailing mobility of coastal sailing runs, as well as direct passages in the open sea. Quantitative works attempting to measure potential sailing mobility have shortcomings related to the use of averaged wind data, thereby losing knowledge of wind variability; non-inclusion of the human factors impacting mobility; and not using methods of measuring coastal sailing. The method presented here was developed to measure potential sailing mobility of coastal sailing runs, based on using the patterns of hourly wind direction and speed variability – and specifically the coastal breeze cycle. The effects of wind variability on sailing mobility are extracted from a large dataset of data at high spatiotemporal resolution, by employing millions of sailing simulations which enable developing meaningful information from big data. This method has demonstrated its applicability to measuring coastal sailing mobility in several developmental case studies in the eastern Mediterranean, introducing realistic measures of mobility that include coefficients of mobility and of time spent waiting for favourable winds. Complementing a previously developed method to measure potential sailing mobility on direct open-sea passages, this new method can now provide a comprehensive toolkit for mapping potential sailing mobility. Such mapping is a valuable input to research on maritime networks and maritime-related developments.