Welcome - first, I like the composition, very original with the neck under water. Composition, the soft side of photography is so important, finding unique perspectives and showing us the world thru your lens is what we hope to see - this is well done.
There is a debate over head angles, most like them level with the lens this has a slight turn away - let's see what other say. Probably be stronger with a head turn towards the camera and a catch light in the eye or brighten it a bit. This is a very solid first post better than mine, I would not crop the shot so tight and apply some selective sharpening in post and go from there. The Nikon can support higher ISO than 360 and this will allow a faster shutter as well, this will help with the sharpening.