The bottom level of a whaler was usually divided into several sections. The lower main hold is located between the main and foremasts. On the outbound part of the voyage the casks stored in the holds would contain water and supplies. As whales were caught and processed, the casks would be filled with oil. Placement of the filled casks in the hold was an important job, as they needed to be balanced, not too many on one side or the other. Casks would come in several sizes and shapes to fill every space.