Genesis 7:17-20

17For forty days the flood kept coming on the earth, and as the waters increased they lifted the ark high above the earth. 18The waters rose and increased greatly on the earth, and the ark floated on the surface of the water. 19They rose greatly on the earth, and all the high mountains under the entire heavens were covered. 20The waters rose and covered the mountains to a depth of more than fifteen cubits. That is, about 23 feet or about 6.8 meters Or rose more than fifteen cubits, and the mountains were covered