The process of passing the dam itself is an interesting experience. Since the water level on one side of the dam is 30m higher than that on the other side, the boat has to ascend to the other side of the dam to continue its voyage. This process is the same as a lock on a canal, where the boat sails into a space resembling a huge water tub, and, after the door to the tub is closed tightly and water is injected into the huge tub to raise the boat (or drained out to lower a boat traveling in the opposite direction). When the water level is in line with that on the higher side of the dam, another door
on the high water side opens to allow the boat to sail out.
Most passengers enjoy watching this experience and the boat feels and looks something like a toy ship in the hands of a child in the bathtub during the whole process!