Here's why:
* All stones are technically "in water": Even stones on land are exposed to water vapor in the air.
* Some stones are obviously not deep in water: Rocks on mountains, in deserts, or on beaches are not submerged.
* Some stones are partially submerged: You might find stones at the edge of a lake or river, where they are only partially covered by water.
So, to answer your question more accurately, I need a bit more context.
Can you tell me what kind of stones you're thinking about, or what situation you're imagining? That will help me give you a more precise answer!