Water inside the earth under pressure? that is an understatement. If the voulume of wather sufficent to cause the biblical flood were under the earth's crust it would be under tremendous pressure, enough pressure to rib the crust of the earth off.
and the Canopy? A massive layer of ice and/or water vapor high above the atmosphere? it would have to be miles thick. so think that sunlight couldn't get through and so thing that the air pressure at the surface woudl be tens of thousands of pounds per square inch. and the trapped heat from this canopy would be well past the temperature needed to melt lead.
Evidence of a global flood? no
There have been at least six mass extinctions.
Flood myths are by no means universal.
evidence? no
Wow! Just noticed you were not an Atheist!

Did you even read any of the links? Funny just discussing the Creeds of the Faith. The two earliest confirm God is maker of heaven and earth. I guess you did not get the memo? God in Job 38-42, had a lot to say about His creation. Check it out!
And God said He will not the destroy the earth with water again-made a covenant with us and the beasts of the earth, but will with fire. If it wasn't world wide, He would not of had to make a covenant with us. Right? "six mass extinctions", lol! Dude, you need to get into the word more.
8Then God spoke to Noah and to his sons with him, saying,
9“Now behold, I Myself do establish My covenant with you, and with your descendants after you;
10and with every living creature that is with you, the birds, the cattle, and every beast of the earth with you; of all that comes out of the ark, even every beast of the earth.
11“I establish My covenant with you; and all flesh shall never again be cut off by the water of the flood, neither shall there again be a flood to destroy the earth.” 12God said, “This is the sign of the covenant which I am making between Me and you and every living creature that is with you, for all successive generations;
13I set My bow in the cloud, and it shall be for a sign of a covenant between Me and the earth.
14“It shall come about, when I bring a cloud over the earth, that the bow will be seen in the cloud,
15and I will remember My covenant, which is between Me and you and every living creature of all flesh; and never again shall the water become a flood to destroy all flesh.
16“When the bow is in the cloud, then I will look upon it, to remember the everlasting covenant between God and every living creature of all flesh that is on the earth.”
17And God said to Noah, “This is the sign of the covenant which I have established between Me and all flesh that is on the earth.”
3Know this first of all, that in the last days mockers will come with
their mocking, following after their own lusts,
4and saying, “Where is the promise of His coming? For
ever since the fathers fell asleep, all continues just as it was from the beginning of creation.”
5For when they maintain this, it escapes their notice that by the word of God the heavens existed long ago and the earth was formed out of water and by water, 6through which the world at that time was destroyed, being flooded with water. 7But by His word the present heavens and earth are being reserved for fire, kept for the day of judgment and destruction of ungodly men.
8But do not let this one
fact escape your notice, beloved, that with the Lord one day is like a thousand years, and a thousand years like one day.
9The Lord is not slow about His promise, as some count slowness, but is patient toward you, not wishing for any to perish but for all to come to repentance.