However, you could use these options depending on the context:
* "The vastness of the world's oceans": This emphasizes their size and interconnectedness.
* "The seven seas": A traditional phrase, referencing the major oceans.
* "The global ocean": Emphasizes their unity as a single system.
* "The oceanic expanse": A more formal and descriptive term.
Ultimately, the best choice depends on the specific situation and the intended meaning.