70% of the earth's surface is a blue ocean, about 80% of the creatures on the earth are in the ocean, and 90% of the goods in the world are transported by the ocean. The ocean provides abundant wealth and endless resources for human survival and development. Navigation is the basis and premise for human beings to know, utilize and develop the ocean. In modern history, China's navigation technology lags behind that of western developed countries. China has made great progress in navigation. But in the aspect of navigation science and technology, it is mainly to learn, draw lessons from, introduce, digest and absorb the navigation science and technology achievements of western developed countries for our use. However, since the implementation of the reform and opening-up policy in China, the maritime industry has developed rapidly and made exciting and world-renowned development achievements in all aspects.

This is the choice of many seafarers, who are mostly engaged in shipping-related business after disembarking. There is no need to float on the boat. For many people, they have a sense of belonging and are closer to their family and friends. After all, the professional requirements on board are very high. With the growth of age, some people can't adapt to development, and it is a wise choice to get off the boat at this time. People who retire from the front line have more advantages in engaging in navigation-related business on land than those who have never been on a ship, and know more about ships and navigation. Because they have worked on ships and have good interpersonal relationships in the industry, this is a huge online market, and it will be more convenient to work. However, they are already familiar with the relatively closed environment on board, and may not be able to adapt to the working environment on land for a while, or they may not know much about the changes in social conditions. Moreover, the requirement of personal ability in land work is all-round, which is difficult for some people to cope with.