Oceans During Hadean Eon

It’s interesting to note that there were still oceans on the surface of the earth during the Hadean eon. Inspite of the fact that the average surface temperature was way past the temperature at which water boils/evaporates.

The oceans existed because of high atmospheric pressure, brought about due to a higher concentration of CO2 in the atmosphere.

So, yes, you can have an ocean on a planet, even if the environment is super hot. Probably not the best of conditions for life (as we know it) to thrive. The main point here is that the atmospheric pressure is what determines whether liquid water can exist on the surface.