The beginning of this poem tells of the old sailor hardships at sea. He experiences he bitter cold of the winter, being alone and isolated at sea, and hunger.
In a thousand ports, and in me. It tells of smashing surf when I sweated in the cold of an anxious watch, perched in the bow as it dashed under cliffs. My feet were cast in icy bands with frost, with frozen chains, and hardships groaned around my heart. Hunger tore at my sea-weary soul. On an ice-cold sea, whirled in sorrow, alone in a world blown clear of love, hung in icicles. The hailstorm flew. (5-17)
Anderson 2
A second central idea is the idea that nothing last forever and remains permanent.
The seafarer knows of three fates that threaten him: illness, age, or death by an enemy.
Thus the joys of God are fervent with life, where life itself fades quickly into the earth. The wealth of the world neither reaches to Heaven nor remains. No man has ever faced dawn certain which of Fate's three threats would fall: illness, age, or an enemy's sword, snatching the life from his soul
(65-71)
A third central idea is salvation. The sailor has a great faith in God and that God will bring him back home safely and keep him safe at sea.
Fate is stronger and God mightier than any man's mind. Our thoughts should turn to where our home is. Consider the ways of permission for us. To rise to that eternal joy. That life born in the love of God and the hope of Heaven. Praise the Holy Grace of the he who honored us, eternal, unchanging creator of earth. Amen.