The question has been raised many a time. The simple logic that people see while asking this question is that they think Air Transport will delivery the carriage faster than the ship will. But instead, people find it hard to believe that Air Transport or Air Delivery of carriage has a problem of scale and volume. Air Transport does not allow to delivery heavy courier carriage services. One cannot afford testing limits, with a lot of risk and huge amount. Whereas on the other hand, ships have humongous size which allows them to ship multiple carriages at one time, making it cost effective. Also, cargo shipment has low probability of crashing with an accident, which makes businesses count on it as a delivery vehicle.