Sea of Dreams

I am pursuing fantasy art ideas and concepts, rather than just drawing things realistically. I have continued my Franklin Expedition inspired drawing. I have decided I want a darker background for the space between the diamond shape and the ship.
Another tricker part of the drawing is the shape of the ‘splash’ where the wave is rising. I need to remove any angular shapes from this area. Of course the main feature of this work is the bizarre clash between the diamond pattern and the shape of the waves, which defies physics. But the ‘splash’ must be separate from this.