I combined 3 pictures to get this picture.
I started off with this underwater image I found on Google Images as the background.
Then I found this picture of the earth on Google Images and used the Magic Wand tool to make it into a transparent, cutting along the outline of the earth and pasted it at the bottom of the first picture. Then I cropped the original image and stretched the image of the earth to completely fill the bottom without making the image look too stretched.
I also found this picture of a woman on Google Images and used the Magic Wand tool to make it transparent, keeping just the outline of the woman and pasted it into the combined picture of the sea underwater and the earth.
I then further used the magic wand and masking tool to clean up along the image and make it appear softer in the final image.
Finally I used a gradient tool to create an outward glow surrounding the woman for a smoother transition and to highlight the focus of the image.