Noah's flood was only 25 ft deep.

I am aware there are certain opinions of the flood that assert it was local, and that it was only 15 cubits deep (24.5 ft deep)

All sorts of thoughts and statements follow these assertions.

Was it really covering the mountains?
That would require several miles of depth, with the ark floating on top in the clouds.

Which is true?

I think he’s saying after it covered the tops of the mountains and hills ot went fifteen more cubits above them

“And it came to pass after seven days, that the waters of the flood were upon the earth. In the six hundredth year of Noah's life, in the second month, the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened. And the rain was upon the earth forty days and forty nights. And the flood was forty days upon the earth; and the waters increased, and bare up the ark, and it was lift up above the earth. And the waters prevailed, and were increased greatly upon the earth; and the ark went upon the face of the waters. And the waters prevailed exceedingly upon the earth; and all the high hills, that were under the whole heaven, were covered. Fifteen cubits upward did the waters prevail; and the mountains were covered.”
‭‭Genesis‬ ‭7:10-12, 17-20‬ ‭KJV‬‬


It seems it covered all the highest hills and then proceeded further until the mountains also were covered

i agree !

I am aware there are certain opinions of the flood that assert it was local, and that it was only 15 cubits deep (24.5 ft deep)

All sorts of thoughts and statements follow these assertions.

Was it really covering the mountains?
That would require several miles of depth, with the ark floating on top in the clouds.

Which is true?

However, we err if we assume that the present-day mountains existed at that time.

Since Mount Ararat is named in connection with the Flood, it was a pre-existing mountain. And the ark rested in the seventh month, on the seventeenth day of the month, upon the mountains of Ararat. (Gen 8:4) Ararat is about 17,000 feet high (about 3.2 miles high). The waters of the Flood were about 25 feet above that height. Therefore taking sea level as the base, the Flood waters were over three miles high.

I am aware there are certain opinions of the flood that assert it was local, and that it was only 15 cubits deep (24.5 ft deep)

All sorts of thoughts and statements follow these assertions.

Was it really covering the mountains?
That would require several miles of depth, with the ark floating on top in the clouds.

Which is true?

The text says "upon the mountains of Ararat", not "on Mount Ararat." It's describing a region, not a mountain. Further, nothing in the text indicates that the mountains existed prior to the flood, and many places were named anachronistically in Scripture.

Makes no difference. It was a pre-existing region which would also have been about the height of Mt Ararat (just like any mountain range).

The text says "upon the mountains of Ararat", not "on Mount Ararat." It's describing a region, not a mountain. Further, nothing in the text indicates that the mountains existed prior to the flood, and many places were named anachronistically in Scripture.

None of the above.

I don't go beyond what is written.
I don't believe that it's a good idea to do so. It detracts from the main point of the story.

Seashells have been found in the tops of mountains authenticating the height of the flood waters.

Some indicate the mountains formed during the flood.

that idea does not fit.

Genesis 7:20
Fifteen cubits upward did the waters prevail; and the mountains were covered.

That reads, "the existing mountains were covered."