and is mentioned in the second stanza:

I must go down to the seas again, for the call of the running tide

Is a wild call and a clear call that may not be denied...

Having obviously spent so much of his life by the sea or on the sea, this die-hard sailor finds that he cannot live without it and that the "call" creates an impulsive desire to return to the sea. Let us consider how this call is characterised: it is a "wild" and "clear" call that cannot be "denied" by the speaker. Note how the words "wild" and "clear" create a picture of the wildness and emptiness of the sea, creating a spirit of adventure which is very attractive and characterises the speaker's thirst for a return to that adventure and wildness that he has experienced in the sea before.

The poem “Sea Fever” by John Masefield is rich in imagery that appeals to all the senses. In order to help you answer your question regarding the sounds of the sea that are recalled, let’s have a look at the lines that allow us to vividly imagine some of the auditory memories that evoke the poet’s longing to revisit his life at sea. As a point of reference, I will remind you that the poem consists of three stanzas, each with four lines.

The first stanza introduces the poet’s longing. All his senses seem to call out for a return to the sea. While the first, second, and fourth lines provide visual images (a tall ship, a gray mist, and a gray dawn), the third line references sounds: “wind’s song and the white sail’s shaking.” The personified song of the wind and the shaking of the sails under the effect of the wind are very distinctive sounds that he very much wants to hear again.

In the second stanza’s first line, we imagine a wondrous sound: “the call of the running tide.” This refers to the rushing sound that water makes as it runs out during low tide and runs back into the shore during high tide. The second line of the second stanza describes this sound as “a wild call and a clear call that cannot be denied.” The sound of rushing water is a primeval force that further compels the poet to return to the sea. In the last line of the second stanza, we come across yet another sea-sound that the poet longs for: “the sea-gulls crying.”

The third (and last) stanza allows us to imagine a particular kind of extended sound, “a merry yarn from a laughing fellow-rover.” A yarn is a story, and a rover is someone who travels around. The poet yearns for the auditory experience of a comrade’s laugh and the kind of colorful story a sailor might tell to pass the time during long days and nights at sea.