Notes: Rod doesn't usually use square canvas. 12x18 or 18x30 is his #1personal preference for landscape or seascape. Pick you canvas shape and size according to your photo reference or crop your painting.
Your painting can be adjusted, to reflect the rules of composition and design instead of painting exactly what you see in nature or picture.
You can crop using masking tape, top and bottom to get landscape size to suit the reference, or perhaps bigger sky, and add some clouds to that higher part, cropping the bottom only.