The poem is intended to be declaimed rather than read. Its use of alliteration relates it closely to normal speech. Even today, many speakers of English alliterate their prose subconsciously.
This verse form was probably an aid to memorisation (as is rhyme) but alliteration avoids the artificiality of rhyme.
Ship burials were common for high status individuals. In this case we have the ship launched on its last voyage with the deceased hero.
Other references and findings show burial with the ship, cremation in the ship followed by burial under a mound, and, in Scandinavia, burial in a grave marked by stones arraigned in the form of a ship.