The Possessed Sea

Between phone calls at work, I glanced out at the sea. There was a sudden shift in the water - or rather, in the nature of the water. The change was hard to define, but the water seemed suddenly deeper somehow, and a different colour, a night-green, and this night-green was slashed with the black of shadows.
I imagine this striking change was due to the sea being choppier than normal - certainly it did not seem like the placid waters of the English Channel. Under the rainy, lowering skies -it seems to have rained continually for weeks now- the ocean took on a more threatening aspect, like a premonition of a storm, or a feverish illness.
With the horizon vanishing into this summers constant white void, the sea took on an oddly disquieting dreamlike quality.
I took another call, and when I next looked out of the window, the sea had reverted back to its usual unremarkable self.