Vast and Powerful:
* The ocean is like a giant, breathing beast whose every sigh sends waves crashing against the shore.
* The ocean is like a swirling, liquid universe with its own secrets and wonders.
* The ocean is like a boundless, untamed wilderness that holds both beauty and danger.
Calm and Serene:
* The ocean is like a mirror reflecting the sky, its surface undisturbed by the wind.
* The ocean is like a soft, blue velvet blanket stretching out to the horizon.
* The ocean is like a whispered promise of tranquility and peace.
Dynamic and Active:
* The ocean is like a restless spirit constantly in motion, its waves crashing and surging.
* The ocean is like a living tapestry woven with currents, tides, and swirling eddies.
* The ocean is like a symphony of sound with its crashing waves, howling winds, and the cries of seabirds.
The best simile for you will depend on the specific context and the feeling you want to convey.