"The Seafarer" is an Old English poem that tells of a man who is singing about the sufferings he endured crossing the ocean during winter. The poem can be found here.
The Seafarer is a man who is traveling across the sea, to seek a "faraway homeland". He apparently likes sailing, and even though his journey was difficult, the next spring he set off again.
Some themes in the plot are loneliness, suffering, and faith. While sailing, he is lonely, and no one understands what he goes through and how hard a life on the open sea is.
He does not know this fact
who dwells most merrily on dry land—
how I, wretchedly sorrowful, lived a winter
on the ice-cold sea, upon the tracks of exile,
deprived of friendly kinsmen,
hung with rimy icicles.
He also speaks about how God is the creator of the "unrelenting ground" and that man is right to fear the Lord.
Mighty is the fear of the Measurer, therefore the earth shall be changed—
he established the unrelenting ground,
Some literary devices are epithets and sensory imagery. One example of an epithet is in the passage above, where the Seafarer speaks of God as "the Measurer [of the ocean]". Sensory imagery is used throughout the poem, some examples are:
Sometimes the swan’s song
I kept to myself as diversion, the cry of the gannet
and the curlew’s voice for the laughter of men—
the seagull’s singing for the drinking of mead.
Storms beat the stony cliffs there, where the tern calls him
with icy feathers.
This is an example of auditory and visual imagery.
It snowed from the north,
binding the earth in ice. Hail fell to the ground,
coldest of grains. Therefore they come crashing now,
the thoughts of my heart whether I should test out
the profound streams, the tossing of salty waves.
This is an example of visual imagery.
The mood is sad because it laments the Seafarer's sorrows and hardships, and finally consoles him with the thought that his "striving" will get him passage into heaven.