Great scene and lighting. I disagree about the bubbles because I think it's better that they're blurry and unfocused since the focus of the scene is clearly the huge squid attacking the vessel. I'd only change the texture of the squid, though. It depends what you're going for, but it looks coarse and sandy over slippery and muscular.
Your brushes work perfect in your style I thought maybe bubbles on the foreground could look more contrast and realistic, but then thought that it will distract the attention too much from the main action and awesome light as always