This is a stunning drawing, and one of your finest. I love the style you have used, and the creativity in it. Her attitude is sexy and the way you have drawn it is fantastic
I do feel you could have used more deeper shading, the hard shading does not fit the picture well. I would like to see you using deeper shades lots of more color, and made the shading softer. Looking at picture, I feel as if she is having her hair flow in the wind more than being undersea. Shading the picture with blues will help this.
Some of the lines feel bulky, especially around the fingers, and her index finger feels awkward to me.
I do love this picture though, and it is probably my favorite out of your whole gallery. I can't wait to see more from you.
I hope my critique helps you!