o Overview
-> Knowledge across cultures
-> Navigational instruments
-> Sails and steering
o Knowledge across cultures
-> Europeans adapted Asian and Islamic maritime knowledge.
-> Chinese compass use spread west through trade contacts.
-> Islamic scholars preserved and extended Greek astronomy.
-> Mediterranean contacts transmitted mathematical learning.
-> Indian Ocean pilots knew routes long before Europeans.
-> These exchanges enabled innovation, not isolated invention.
o Navigational instruments
-> A magnetic compass indicated direction beyond sight of land.
-> An astrolabe measured the angle of the sun or stars.
-> Mariners used these angles to estimate latitude at sea.
-> Latitude measures distance north or south of the equator.
-> Astronomical charts recorded positions of heavenly bodies.
-> Coastal charts mapped ports, hazards, and sailing routes.
o Sails and steering
-> Lateen sails spread through older Mediterranean networks.
-> Their triangular shape aided sailing at angles to the wind.
-> Tacking used angled courses to make progress upwind.
-> Square sails supplied power when winds blew from behind.
-> Combining sail types balanced maneuverability and speed.
o Overview
-> Ocean ship designs
-> Winds and return routes
-> Trade and naval power
o Ocean ship designs
-> Portuguese caravels were small, maneuverable sailing ships.
-> Shallow drafts aided coastal exploration along Africa.
-> Larger carracks carried provisions and cargo across oceans.
-> Their storage supported longer voyages far from supplies.
-> Dutch fluyts carried bulk freight with relatively few crew.
-> Lower operating costs helped Dutch shipping compete.
o Winds and return routes
-> Sailors combined instruments with practical ocean knowledge.
-> Atlantic trade winds aided westward tropical crossings.
-> Westerlies farther north helped ships return toward Europe.
-> Portuguese sailors used ocean loops to find favorable winds.
-> Indian Ocean monsoons reversed with seasonal changes.
-> Pilots timed departures to winds rather than sail directly.
o Trade and naval power
-> Larger cargoes lowered transport costs per unit of goods.
-> Better route knowledge made repeated ocean voyages feasible.
-> Shipboard cannon helped fleets threaten rival ports.
-> Armed shipping linked commercial travel to imperial power.
-> Technology still required money, crews, and state backing.