Figured as much. Thank you. You've made a good many assumptions that must be taken on faith, beginning with the assumption that the biblical text is false WRT literal history, and ending with the assunmption you have an accurate figure to start with WRT the amount of water present on earth.With those assumptions in mind I can do the same math and come up with the same result. But there is a worldwide record of death buried in the earth's sediment; a record showing beasts of the sea in what are now deserts, showing former life in polar regions that are now uninhabitable. This would be expected if the biblical text is accurate.
The segregation of those sediments into fine layers would not. The apparent faunal succession in them would not. The exquisite preservation of tranquil surface features at various depths in one place would not. The preservation of glacial scraping and dry-land volcanic ash deposition would not. The list goes on and on.
When honest creationist geologists went looking for the Flood residues in the 1700s and 1800s, they couldn't find them. After a while, all the honest people stopped trying to force the result.