Use a fish tank. Get one long enough to hold your camera. You may need some extra weight to sink it about 6 inches into the water. If you tip foreward you have a shot under water, if you tip it back you have a shot above water.
Some rain-x on the glass will help to bead the water off faster. In a pinch a potato will do the same thing. Just cut the potato in half and rub it on the glass.
If your trying to be creative with audio remember that your wireless reciever will not work if it's below the surface of the water. It has to be up higher.