1. Create a new document with a size of 1280×1024 pixels and a resolution of 300 pixels. Then create a new layer and use the Rectangular Marquee Tool (U) to select the entire image. Now choose Layer Style > Gradient Overlay. (Fill according to the values in the picture below)
2. Now we have got an effect like the picture below. Next we will draw an ocean floor scene on this image.
3. Create a new layer, select the paint bucket tool, and fill it with the color code #003366.
4. Select this layer and go to Filter > Render > Clouds.
5. Set the blending mode in the Layers palette to Color Dodge. The picture below is the effect we got.
6. Then we select the Add Layer Mask button at the bottom of the Layers palette.
7. Select the mask itself, and then use the Gradient Tool (G) to draw a gradient on the layer. The top of the layer will become transparent as shown in the picture below.
8. This step is to find an underwater scene on the Internet, as shown in the picture below:
9. Using the eraser tool, we can erase the remaining part except the water surface.
10. Move this image to the top of our original image.
