Buoyancy

[ponjavic]

would there be an upthrust or not if a perfectly smooth object was on a perfectly smooth ocean floor?

I expect that since there is no water beneath the object there is no pressure to provide an upthrust, there would only be pressure above the object creating a downward force!?

[ceptimus]

If you're saying there is no room for even a molecule to get between the object and the ocean floor, then the object is actually a part of the ocean floor. And in that case, I think you're right - the 'object' would be held down by the water pressure.

[ponjavic]

and if there would be room for just one molecule?
Does the fact that they are perfectly smooth mean that there is no room for the molecules?