Stowage plans or bay plans are plans which determine the place of each and every container loaded on a container vessel. These plans are critical for the sea worthiness of the vessel by balancing out the weights but also for the profitability of the voyage by limiting the future needed offloading move and operations.
Every container move represents an operational (crane fee) cost and a time cost, and for example, if you need to move 2 containers off the vessel to reach the one you want to offload and then need to put those 2 containers back, 5 moves are required instead of a single one – meaning this offload operation will have cost 5 times more than it could have.
A well-built stowage plan (commonly assisted or built by computer programs) should help avoid any unrequired move.