New Revised Standard Version
And the waters swelled on the earth for one hundred fifty days.

Contemporary English Version
A hundred fifty days later, the water started going down.

New American Bible
And when the waters had swelled on the earth for one hundred and fifty days,

Douay-Rheims Bible
And the waters prevailed upon the earth a hundred and fifty days.

And the waters prevailed upon the earth a hundred and fifty days.

Genesis 8:3,4 And the waters returned from off the earth going and coming: and they began to be abated after a hundred and fifty days. . . .

compare with ver.

Genesis 7:11 In the six hundredth year of the life of Noe, in the second month, in the seventeenth day of the month, all the fountains of the great deep were broken up, and the floodgates of heaven were opened:

of this chapter. The breaking up of the fountains of the great deep, and the raining forty days and nights, had raised the waters fifteen cubits, or twenty-two feet and a half, above the highest mountain; after which forty days, it appears to have continued at this height one hundred and fifty days more.