In my another post (Does bridge actually refer to the part on which pedestrians and vehicles pass through in everyday English?) I said
Parts of bridge piers pointed out by red square are under the water, which we can't see directly in the image.
when describing this image
Actually, I am not sure whether I used the right preposition.
Take the bridge pier pointed out by red square as our running example, part of it is out of the water, how should I describe the other part? Should I use under the water or "in the water"?
I've searched a bit on ELL, none result.