You can go to a nearby junior college maritime school for training and study, but the secondary school is rubbish. After passing the qualification, go to your own unit or school for introduction.
Call the Maritime Safety Administration to ask where to go for training, and then go to the unit or training institution for introduction after passing the exam.
Signing an orientation agreement with the recruiting unit is to entrust training, and then go to the signing unit to board the ship after passing the examination.
Generally speaking, the above three forms are direct recruitment (official crew), domestic agent and assignment ~ ~ ~.