To shoot a picture half in and half out of the water, you combine the two elements of our planet, the air world and the water world.  And this very thin surface of the water that scientists call the meniscus is a gateway, a division between these two worlds.  That’s why these pictures are popular, because you literally are invited into this other world.  You see the difference between two things.  You see the difference between sunlight and shadow on the surface, and color and depth beneath, and the trick is to combine the motion and the creature or the place underwater with the best that the atmosphere — the air world — can afford.  They’re tricky in terms of composition and just in terms of creative thought.  They’re more tricky technically, because you have to make sure everything’s sharp, and you have to be able to light the bottom part of the frame, and you have to expose the upper part of the frame.  The hardest thing about taking a picture that’s half in, half out of the water are droplets on the dome of the camera.