Here's a quick underpainting done with a bristle brush, pastel and alcohol. Got the basic values and colors of this beach scene at Breezy Point, New York.
I tried to keep it fast and rough to convey the surf and get this done in ten minutes. More layers of action and color to add to this. Sunny and 85 on the beach today!
Here's the reference photo. I'll finish this one at my beach house studio: