The sea in the dream represents "hope". Dreaming of swimming in the vast sea indicates that the dreamer has found hope again after suffering and can set a reasonable goal for himself. Through his efforts, he can finally achieve great success.
In addition, such a dream has a moral, suggesting that the dreamer thinks that few people can understand themselves and always work alone on the road of career or life.
Dreaming of fish means getting rich. Homophonic, fish is homophonic with the word "feng", and fish represents wealth in people's minds. Probably because for primitive people, catching fish is wealth.