Comp a cool image using Transform tools and layers modes
Compositions don’t always need to have multiple images to work. Hit Cmd/Ctrl+J to make a copy of the Background layer, then go to Edit>Transform>Flip Vertical to turn it upside-down.
Select the Rectangular Marquee tool and draw over the canvas’s top half to hide it. Invert the selection via Cmd/Ctrl+Shift+I, then apply a mask to this layer to reveal the original.
Use the Move tool to reposition the top layer so it lines up with the horizon of the original. Go to Filter>Distort>Ocean Ripple to load the Filter Gallery. Use this to apply a wave to the reflection and hit OK.