I stood on the bluffs high above Drakes Beach just after the sun had dipped below the horizon. The high bluffs shadowed the beach below, while the light of sunset still reflected from the incoming surf. I shot a sequence of images at various shutter speeds.
If you are curious, the faster shutter speeds came out better than the slower ones at the same EV value. Across the board, I intentionally underexposed by about two f-stops (or by a factor of four) to make the beach go even darker while still picking up the colors in the water.
Back at home, when Phyllis and I looked at the sequence in Adobe Bridge, the thumbnail looked to us like a scalloped sea shell on a black background. I processed the photo in Photoshop to emphasize this effect.
[Nikon D300, 18-200mm VR zoom lens at 200mm (300mm in 35mm terms), 1/250 of a second at f/6.3 and ISO 100, tripod mounted.]