There were (and are) costs associated with any trip across the ocean and the necessity that the trip be completed as quickly as possible because time is money for seafaring concerns. When your "cargo" is human beings, you want to get as many people as you can on the ship, because you are likely being paid "by the head." You want to deliver them as quickly as possible, before they die. During the course of the voyage, you want to feed the slaves as little as possible because of the cost, and you want to have as small a crew as possible because the crew must be paid. All of this, in addition to the callousness with which the slaves were regarded, as less than human really, led to the dreadful conditions of the Middle Passage, being confined to the depths of the ship, the crowding, the inadequate diet, and the cruelty that was a result of a few men trying to intimidate and restrain a large group.