I use these slides and we add high movement for the words "Higher than a house, higher than a tree" and a low movement for "underneath the water, underneath the sea".
Then on which one could it be, I sing either do or do' and a picture of a high or low thing is showed. The kids plop down or create a low action for if they think it is a picture of something that lives below the sea. They make a high motion if they think it is something that would be higher than a house.
My slides look like this: