Photoshop :: Insert Group Of Faces Below Into Larger Image With Black Background?

I would like to insert the group of faces below into a larger image with a black background.  I would like to give the impression that they are underwater and we are looking down on them through the water.  (Imagine a setting where we are standing beside a stream and looking down into the stream, where we see the faces.)  I find several tutorials for creating underwater scenes in which the camera position is underwater, but none in which the camera position is above and looking down into the water. 

CS5 on a Mac.