I settles on this composition as I wanted to highlight the arch rock and I was drawn to the leading lines of the rock formations just below. I started shooting just as the sun set behind me focusing on capturing an image with strong foreground elements of breaking waves. At this point the tide was receding and I only was able to capture two or three images when a big wave came in and actually splashed into the foreground. Once I was happy with my wave shot, I then dialed in an exposure for the soft pink and blue sky about 20 minutes after sunset by spot metering the sky and opening up the exposure by 2/3 of a stop to make sure I moved the highlights as far to the right as possible before clipping out details. That would allow me full color and tonal control over the sky in the RAW conversion. The two files were hand blended in Adobe Photoshop CS5 for maximium dynamic range.
Tech Details: Nikon D3, 16-35mm, Singh Ray LB Polarizer, Gitzo Tripod w/ Arca Swiss head, MC-30 cable release, 1/2 a second at F16 for the water and rocks and 1/15 at F16 for the sky.