Imagine a vessel with an absolutely flat bottom. And put on the bottom a flat piece of wood so that it lies completely on the bottom, and there is no water left between it and the bottom.
Question: What is the force of the archimed with which water acts on this piece of tree?
Your missing theoretical physicist.

<><><>>
In Wikipedia, which is used by schoolchildren, it is stated that the law of Archimedes is not applicable to this case. Popular - there is no pressure of water on the piece from below, it will not pop up. Because of this, sometimes submarines can not break off from the bottom.