Answer: had to take into account environmental factors such as the timing and direction of the monsoons
Step-by-step explanation:
Sea voyages in the Indian Ocean were yet often deadly because of monsoons, and still required extended journeys, as well as prolonged stops in harbors where they had to remain, even up to several months, until the winds would shift direction. The development of long-distance trade routes relied on environmental knowledge, including an exceptional understanding of the monsoon winds.