I like this image a lot; however, I gave it a 5. The water is almost 50% of the image and mostly out of focus. As negative space, it really doesn't help the image. If might want to try a square crop or even a horizontal crop to minimize the water as much as possible without removing the beach/water connection.
Great job! I love the clarity and movement in the water closest to the crab leg.. I loved the color of the sand, and it's hint at the moisture stored therein. It meets the theme of the challenge perfectly! I'm voting it a 6 just because it's not a very interesting shot overall.
Not entirely happy about the composition, (too much dead stuff upper right, to include the second shell). Crop below the upper claw and 1/3 (1/4?) in from the right. LERV the colours and textures there.