If the world is covered 72% water on a big sized globe. The scale usually shown, is that the oceans are but a mere thin layer covering the earth, it seems. Its not so silly to have that opinion (an assertion if you want) that 28% of the water ( not 28% size of the total earth mass) could recede below.
Lots of proven and accepted scientific observations started out being ridiculed, such as continental drift and evolution via natural selection. But these "absurd claims" had evidence to back them up, even if they were not widely accepted. The scoffers were simply biased and ignorant, certainly understandable, even forgivable.
But there is absolutely no evidence or physical mechanism or observed phenomenon that 30,000 feet of water spewed over the earth and then receded back down the drain. This is just religious silliness at its finest.
Better is that we know that there is no solid dome over the Earth and no 'water above' for it to keep out. Learner's problem is that he is attempting to act the Biblical apologist but doesn't know the Biblical cosmology.
I find it ironic that Biblical apologists continually add to or subtract from what is in the Bible in their apologetics even though, according to Revelations, such amendments will condemn them.
Proverbs is a bit less severe. There is just warning not to add to god's words "lest He rebuke you and you be found a liar."