Ship captains were under orders by slavers to deliver only saleable slaves. Starving, sick or troublesome slaves were often thrown overboard into the ocean to drown. Sometimes Africans were kept on deck chained together with long chains. There were times when they would jump overboard, taking every other chained slave with them, to avoid their unknown fate. Many ships kept extra crew members on deck to prevent this from happening. At other times crew members would throw slaves overboard as a warning to other slaves. If the ship was running out of food or water, all the slaves would be killed to save the crew from starving.