One of the problems with Genesis and that which we know of the origins of how planets form - water came much later.
An old earth would probably have had hills and valleys and as water formed by whatever means, gravity pulled it to the lowest area and formed the seas.
The concept that the earth was w/o form and void and everything was water is thus implausible. Earth was never a pure water planet despite being 70% water.
We pretty much know the aspect of Pangea and how the continents drifted apart. Life evolved on these continents very differently yet there are similarities in topography suggesting the same influences of wind and water erosion forming mountains and evidence of a very old earth.
None of the ME authors knew of Aus or even Japan let alone Southern Africa and Antarctica. Their "world" was seen as flat and observation of the sky, well it does appear to be a dome from ground level. The curvature of the earth is very apparent at sea level when one looks out yet they were flat earthers. To see the curvature inland, one needs altitude and lots of flat land surrounding. How they could not figure this out beats me
They did not understand the water cycle and thus springs were assumed to be "fountains of the deep" The rain gods and these springs were not correlated and Genesis gets it totally wrong where it says there once was no rain. Right there, that is a physical impossibility but is IMO a set up to use this factoid of the earth spouting forth fountains to the extent the mulims claim the force was so great that that is what pock marked the moon as rocks were thrown out into space.
The evidence of Pangea, the fludd freaks then suggested that this coincided with Noah's fludd and in fact the springs gushing forth, the water went 20km into the sky and the continents moved at speeds of up to 40km/h away from each other. Yup a YEC claim.
We all know when the earth has a hiccup with subduction and the devastation that brings yet the YEC folk hold to this as a possible explanation to make the Genesis account fit.
The forming of supercontinents and their breaking up appears to be cyclical through Earth's 4.6 billion year history. There may have been several others before Pangaea. The fourth-last supercontinent, called Columbia or Nuna, appears to have assembled in the period 2.0-1.8 Ga (wiki)
So non-science or simply nonsense prevails trying to validate the flood claim.
However this fludd claim is suggested to be the whole world was covered by water at the creation event aka the "Great Flood", mileage varies.
The only thing the theist then does well how do we know back then they did not move away faster which boils down to I make up a story and then the onus is on you to disprove it. Sorry science does not work that way.
Because dogmatic theists are hopelessly unschooled in basic geology and geography, they mix the stories up and no one is the wiser unless they fact check.
Based on the simple fact that all continents originated around Africa, then it stands to reason we should see identical fauna and flora right around the globe, but we don't. Sure we get elephants in the Indian subcontinent but they are vastly different to the African elephant, the mountain lion in the USA is not found in Africa neither are tigers.
Fossils show us woolly mammoths and while they are similar to elephants they are another species (now extinct)
Everything shouts adaptation, old earth, evolution, yet somehow the bible literalist gnaws at his own arm to try make the bible story fit the now irrefutable evidence in opposition to the bible claims.
The bible really does not add value to the ascent of man. All it shows is wilful or selective ignorance of times past. It really is not a book of morals either or else we would be stoning kids, gays and adulterers yet we do not do that anymore now do we? (muslims excluded of course)
Yet the whole premise of Genesis revolves around a fundamental doctrine of original sin. W/o OS the rest of the story, no matter how fascinating one may find it is moot and irrelevant.
Not once has the theist been able to demonstrate creation. All they do is (sometimes) adapt to the new discoveries (aka facts) and reinvent themselves which has theistic evolution as a inconsequential counter. When they discovered DNA this was obviously too "complex" to have simply come about on its own and as such the theist laid claim to what was not even known 100 years ago.
4.5-4.7 Billion years folks, that is the undisputed age of the earth, plenty of time to develop from simplex to complex forms.
The bible authors were totally unawares of the basic fundamentals of how stuff works so that is why the sun is created after plants and out of sequence. W/o the sun, we would not have a ball of water but a ball of ice and nothing would survive. Simple logic and very basic biology tells us this could not have transpired in this manner or order.
Of course there is always magic