I love the reflections of the water, and the bubbles. I would have like to have seen the composition of the line and the girl on more of an angle, and also would have preferred to see her "arrow straight" with her legs straight out and her arms by her sides, so that she mirrored the line.
Title's okay. Picture's technically fine but I would think another angle might provide a more visually interesting picture. This is just kind of centered which sometimes doesn't give the eye anywhere to go.
The blue is subtle but works. Love the air bubbles, I think that really makes the image for me. No idea how much control you had on this shot, but in a perfect world I'd love to see the blue tiled line go diagonally across the frame and also have her almost mirroring the line with an elongated body instead of her current pose. The light patterns on the bottom of the pool is neat.