A fairly simple one this time. I belatedly realized that Photoshop has an "Ocean Ripple" filter that provides a pretty realistic watery effect, but there's something to be said for simplicity.
My take on the kraken is inspired by the Hook Island sea monster, which I think is a pretty awesome cryptid even if it was just a weighted plastic tarp. The kraken was said to float quietly like an island and then suddenly submerge, dragging down any ships unlucky enough to be tethered to it. According to a medieval bestiary translated by T.H. White, it serves as a metaphor for unbelievers who trust in the devil: "They anchor themselves to him, and down they go into the fire of Hell." This also happens to be more or less the plot of the sci-fi horror movie Event Horizon.