Gorgeous, colourful work - such as we'd expect out of Delya! I love to see you do softshading, and the underglow of ocean light gives it such a 3D feel.
My only beef is with the shirt. The softshading on that doesn't stand out as much - there's not enough contrast between lights and darks, and though the shading is there, it blends in with the shirt so much that it looks like part of the pattern.
Perhaps if you threw a few purples or blues in to deepen the shading, it'd work well.
Other than that, a beautiful summery picture that transports the viewer.

Agreeing with the above about the line about her lips needing to be inverted. Well, not needing, per se, but unless her mouth itself is supposed to look fat, it would be more aesthetically pleasing if that curve was downwards instead of upwards.

The line of her jaw that's directly below her hair (right of where her ear is) looks out of place, and makes her face look entirely separate from her neck and ear. It doesn't really stand out, but it does give a sort of mask-y impression.

The forearm that's closest to the viewer looks rather... off. The elbow shouldn't be that thick, especially not with a wrist that thin. The hands in general are a bit small, but the wrists stand out as being really really tiny because the elbow is so thick.

I got nothing on the shading. The use of colour is absolutely gorgeous, especially the saturation levels. The texture on the hair is lovely, and the skin tone works beautifully. The backroudn is simple but effective and well painted, and definitely helps the underwater impression. All-around, it's just plain pretty. :>