The waters prevailed fifteen cubits upward, and the mountains were covered.
Referenced Verses
Ps 104:6 : 6 You covered it with the deep as with a cloak. The waters stood above the mountains.
Jer 3:23 : 23 Truly in vain is [the help that is looked for] from the hills, the tumult on the mountains. Truly the salvation of Israel is in Yahweh our God.