Final answer:
The lines from "The Seafarer" illustrate the characteristic of poetic inversion in Anglo-Saxon poetry.
Step-by-step explanation:
The characteristic of Anglo-Saxon poetry illustrated by these lines from "The Seafarer" is the use of poetic inversion. In these lines, the natural word order is inverted for the purpose of maintaining the rhyme scheme and rhythm of the poem. For example, instead of saying "The hoarse rough verse should roar like the torrent," the poet writes "The hoarse rough shore should roar." This inversion enhances the sound qualities of the rhyme and maintains the flow of the poem.