In "The Seafarer," there are three parts. The major portion describes life on the sea; a small section reflects life on land; and, the third part is much like a prayer which speaks to the habits of mankind and its beliefs about death, and the part God plays in rewarding the worthy.
In answer to the question, the author goes on in great detail about the trials and tribulations of being a sailor: the loneliness and the physical discomfort. He speaks to the endless work and the cold; he describes the empty comfort of the animals of the sea and sky.
For a very brief time, the author speaks of life on land, and the sea's siren call--irresistibly drawing him back again and again, even in light of the suffering he endures.
The passion of cities, swelled proud with wine
And no taste of misfortune, how often,
how wearily I put myself back on the paths of the sea.
He recounts the passion of the cities, the influence of wine, and the inability of the society of men to deal with hardship. But he recalls that in light of this, he still returns to the harsh, often unforgiving sea. Perhaps life would be easier in the city, but perhaps, too, he feels closer to heaven with the hard and honest work of sea life.
It is here that his attention turns to God and the rewards of a life well-lived. He notes that what a man may earn materialistically will not follow him to heaven. He states that the praise of men means nothing to one who is dead--but living for the rewards of heaven is what matters most in life: to find oneself in the company of God and the angels is what has true value.
The seafarer may simply be imparting his own form of wisdom: life on the land was empty and meaningless for him. Life on the sea was almost unbearable at times, but his life as a seafaring man has brought him closer to God and his heavenly reward.