* Personification: The world is given human characteristics by being described as having an "arm" and being "crested."
* Metaphor: "Ocean reared arm" is a metaphor comparing the ocean to an arm, symbolizing its vastness and power.
* Hyperbole: "Bestride" implies an immense size and power that exaggerates the individual's presence.
The overall effect is a grand and imposing image that emphasizes the individual's dominance and connection to the natural world. This is a common technique in epic poetry, where heroes are often depicted as larger-than-life figures.