a couple miles isn't that deep...
In my point of view, the Biblical Flood was directly linked to the breakup of Pangaea. The Mid-Ocean Ridges and fissures under the ocean. It has been stated even by atheists that a large water content used to be apparent underneath the crust. In the Bible, there are parts that go along the lines of, "and the fountains of the deep burst forth". By looking at this and going by other data, the observable continental land mass at that time would have exploded (causing the fissures) with "fountains" of water gushing miles into the air for a long period of time. This leads to the speculation of the odd wording where it then says, "it rained for 40 days and 40 nights". The gushing water would have completely oversaturated the atmosphere, which would be a perfect reason for the seemingly monsoonal rain.
Check this:

You can see that the Mid-Atlantic Ridge is shaped to a dime to the PRECISE shape of the ENTIRE African coast, molds to South America very nicely, and imitates the east coast of North America. In my view, the Mid-Atlantic Ridge is the main breaking point that forced out the large quantity of water from under the Earth's main continental land mass.
Other things that are a stretch, but possible things to contemplate:
> The face of the moon that faces the earth is full of craters, but the back side has relatively few in comparison. If the water ejecting from the Earth was powerful enough that some of it was able to actually exit the gravitational pull, it would have frozen on contact with the extremely low temperatures of space. There also would be nothing to slow it down. The crystals would be attracting each other by their own gravitational pulls (everything has some gravity) to form small frozen balls of ice, which would be pelting the moon.
> Some Creationism scientists think that some of the water crystals formed large enough lumps that they would be affected by the sun's gravity. This would be an idea to where comets originated from. Sounds quite stretchy, but still possible.
Wow this Sir Dooble post. :)