We all know about the oceans, continental shelves, and the sea bed. If we measure the depth of sea from beaches in shore, it continuously increases as we proceed away from the shore. In deep oceans the depth may be of the order of thousands of meters below mean sea level. Ships do not encounter any problems in the middle of the oceans as the depth of water is so huge. But as they approach shore, the depth keeps on reducing and sometimes it may be shallow that the ships cannot transit through. Thus due to the shallow depths, the ships cannot come inside ports and deliver cargo. As the cargo is loaded, the ship sinks more and her draft increases. To navigate inside a port with such a great draft, there is always a threat for grounding. Also it is not possible for any Captain to get familiar with the port depth conditions of all the ports in the world. It is also to be noted that the size and the mass of huge ships make it difficult for manoeuvring. The distance of stoppage of these huge ships like super tankers are in miles. Thus every port decided to train and employ their own people as Pilot, thus enabling the ships to reach port without any difficulty. As said earlier, a Pilot is one who is highly experienced and skilled with a better understanding of the port waters on which he is employed. But for all legal aspects, The Master or The Captain remains in command and The Pilot is considered to be a senior adviser.