A speaker sits by the water at dawn and finds a quiet, almost surprising pleasure in the sea. Instead of describing waves or colour, the poem borrows the language of writing: the sea has "grammar" and "diction," as if its sounds and rhythms were a kind of speech that can be read and enjoyed. That pleasure is so strong it "exceed[s] all joy," a big claim made in a calm, understated voice.
Against this, the speaker admits to being tired of other people: "I weary of company." The sea seems to offer a conversation that human talk can't. The last line, "The papers thin," is more open. Judging by the imagery, it might mean the pages of the day's reading or writing are losing their weight beside the sea, or that the speaker's own concerns are wearing away. Either way, the mood is solitary, still and quietly content, with a slight edge of fatigue.