Aside from the facts that 1.) most of the planet is covered with water, 2.) most of the geologic record is one of sedimentary deposition, 3.) there are human records denoting a world wide deluge at some point, 4.) all of the above took place before you became an observer, and 5.) you are predisposed to reject the authority and accuracy of the biblical texts, it is no wonder you cannot find the pesky thing.
Why bring up the geological record? The flood is commonly placed at about 2350 BC.
You want to find something 4350 years old don't waste your time looking about in the rocks; send the geologists home and look in the soils. The creation websites have wasted all their time researching flood geology, when the clues are in the soils.
What do you say about mtDNA continuity for over 10,000 years in North America with no break, and no shift to Middle Eastern (Noah's wife) mtDNA?
What do you say about continuity of Native American occupation for over 13,000 years on the west coast?
(Never mind, I know. All the dating is wrong. Science is all wrong.)