Yes, you can, but it's difficult. Generally speaking, Dalian Maritime University's own college applies for its own university's major, but other schools are not easy to test. Our Shanghai Maritime University generally reserves the number of undergraduate courses for several specialties below the school.

And the majors that can be promoted to undergraduate courses are very limited. Only a few majors. Generally, these majors are not very good. Like you said, change your major. I guess you want to change your major to an undergraduate degree in marine engineering, and then you want to take the National Maritime Safety Administration? Because national civil servants can only take undergraduate courses, and there is no similar undergraduate course for water majors, that is, there is no marine engineering major for you to change majors.

I think you'd better go to correspondence or night school in the future, so as not to waste time. If you successfully upgrade to higher education, you will only switch to other majors, and your employment will become more problematic in the future. At present, the threshold of academic qualifications is still very high, and there is still a big difference between undergraduate promotion and unified undergraduate recruitment.