What's the difference between a seaman's card and a passport?

Seaman's card is a necessary document issued by the Ministry of Communications to ocean-going crew members. When sailing to another country in the ocean, the immigration department needs to check and sign a visa on your seaman's card, and you need to take it with you when you play in the fields. Seafarers need a visa on the seaman's card when going abroad or returning home.

Ocean-going seafarers also need passports, because some countries, such as the United States, Singapore and Indonesia, do not check seafarers' certificates, but apply for passports and visas. You must have a passport to get a visa to these countries. Passports are applicable to all China citizens who go abroad, while seamen's cards are only applicable to ocean-going crew members.