Dhow Navigator

Historic Indian Ocean Voyage Calculator

Click a port to set departure, then click another for destination

Voyage Estimate

Route
Sea Distance
Eff. Speed
Estimated Voyage Duration
Route Strategy
Historical Context

Monsoon Seasons

SW Monsoon (May–Sep)Africa → India favorable. The kaws peaks June–August.
NE Monsoon (Oct–Feb)India → Africa favorable. The azyab reaches Zanzibar by late November.
Transition (Mar–Apr, Sep)Variable winds; used for repair and short hops.

Vessel Specs

Sources & Data Notes

Alpers, E. A. (2013). The Indian Ocean in world history. Oxford University Press. https://global.oup.com/academic/product/the-indian-ocean-in-world-history-9780195337877
Tolmacheva, M. A. (2016). Navigation in the Indian Ocean and Red Sea. In H. Selin (Ed.), Encyclopaedia of the history of science, technology, and medicine in non-Western cultures (pp. 3349–3355). Springer. https://doi.org/10.1007/978-94-007-7747-7_8808
Pouwels, R. L. (2002). Eastern Africa and the Indian Ocean to 1800: Reviewing relations in historical perspective. The International Journal of African Historical Studies, 35(2/3), 385–425. https://www.jstor.org/stable/3097619
Smithsonian National Museum of African Art. (n.d.). Monsoon dhows. https://indian-ocean.africa.si.edu/monsoon-dhows/
Horton, M., & Middleton, J. (2000). The Swahili: The social landscape of a mercantile society. Blackwell.
Tibbetts, G. R. (Ed. & Trans.). (1971). Ahmad ibn Majid, Arab navigation in the Indian Ocean before the coming of the Portuguese. Royal Asiatic Society.
Ruiz-Gálvez, M. et al. (2021). Quirimbas islands and the Swahili gold trade. J. Arch. Sci.: Reports, 38, 102985. https://doi.org/10.1016/j.jasrep.2021.102985
Vessel speeds (1–9 knots), route timings, and voyage durations synthesized from Tolmacheva and Tibbetts (Ahmad ibn Majid's 15th-c. sailing instructions). Vessel dimensions based on comparative ethnographic surveys. Coastline geometry simplified for visualization. All route strategies are speculative reconstructions.