But the most important thing was the wind. The Indian Ocean is home to a set of very special winds called monsoons. You generally hear about monsoons in the context of rain in India, but rather than thinking of monsoons as the rain itself, think of them as the wind that brings a rainy season. The great thing about seasons is that they come regularly, and so do the monsoon winds. So if you were a sailor, you could count on the wind to bring you from Africa to India if you sailed between April and September, and one that would bring you back to Africa if you sailed between November and February. In fact, these winds were so predictable that early maritime travel guides often listed ideal times of departure down to the week and sometimes even the day. Predictable winds made trade a lot less risky, like back in the day when the only power for ships were sails and oarsmen, your cargo might not arrive on time, or it might spoil, or you might die, all of which are bad for the health of global economic trade.