Select the waves and the rectangle klone hidden under them, and apply a Fractal Clouds fill. The idea is to simulate a wave-effect of water that is not too calm. So the first set of stripes is where the water is rushing from the crest of the wave to the the base of the wave. The rectangle behind the stripe/waves-objects is the base of the waves, and the second set of stripes is the water rising from the base of the waves to the crest.

Nudge the two wave-stripe-objects to respective sides a bit so the underlying rectangle becomes visible. Apply a 10 pixel feathering to each wave-object. Then for each of the three objects we now have to change the "direction" and the colors of the fractal fills as indicated below.

After some fiddling with the Fractal fills we should get a fairly good restless sea effect.

NOTE: The greater the difference between the three Fractal fill angles, the stormier the sea will appear.

Now is a good time to save your image and to take a short eye break.