That is totally false.
The history of the Patriarchs as recorded in the Real Book of Jasher -not the pseudo Jashers that are out there and proven false, but the real Book of the Upright that correlates with Torah totally, says this:
34 In his five hundred and ninety-fifth year Noah commenced to make the ark, and he made the ark in five years, as the Lord had commanded.
chapter 5:35
Then Noah took the three daughters of Eliakim, son of Methuselah, for wives for his sons, as the Lord had commanded Noah.
only Enoch's descendants, through Methuselah, son of Enoch, the seventh from Adam, through Seth, survived the flood in the Ark.
Noah's wife was the daughter of Enoch, also:
13 And Noah was a just man, he was perfect in his generation, and the Lord chose him to raise up seed from his seed upon the face of the earth.
14 And the Lord said unto Noah, Take unto thee a wife, and beget children, for I have seen thee righteous before me in this generation.
15 And thou shalt raise up seed, and thy children with thee, in the midst of the earth; and Noah went and took a wife, and he chose Naamah/Naomi, the daughter of Enoch, and she was five hundred and eighty years old.
16 And Noah was four hundred and ninety-eight years old, when he took Naamah for a wife.
Can you explain how the Kenites which are the descendants of Cain have survived the Flood? The Kenites are mentionned AFTER the Flood?.... Good swimmers maybe.
http://www.kingjamesbibleonline.org/Kenites/
"KENITES" in the KJV Bible
Genesis 15:19 | View whole chapter | See verse in context
The Kenites, and the Kenizzites, and the Kadmonites,
Numbers 24:21 | View whole chapter | See verse in context
And he looked on the Kenites, and took up his parable, and said, Strong is thy dwellingplace, and thou puttest thy nest in a rock.
Judges 4:11 | View whole chapter | See verse in context
Now Heber the Kenite, which was of the children of Hobab the father in law of Moses, had severed himself from the Kenites, and pitched his tent unto the plain of Zaanaim, which is by Kedesh.
1 Samuel 15:6 | View whole chapter | See verse in context
And Saul said unto the Kenites, Go, depart, get you down from among the Amalekites, lest I destroy you with them: for ye shewed kindness to all the children of Israel, when they came up out of Egypt. So the Kenites departed from among the Amalekites.
1 Samuel 27:10 | View whole chapter | See verse in context
And Achish said, Whither have ye made a road to day? And David said, Against the south of Judah, and against the south of the Jerahmeelites, and against the south of the Kenites.
1 Samuel 30:29 | View whole chapter | See verse in context
And to them which were in Rachal, and to them which were in the cities of the Jerahmeelites, and to them which were in the cities of the Kenites,
1 Chronicles 2:55 | View whole chapter | See verse in context
And the families of the scribes which dwelt at Jabez; the Tirathites, the Shimeathites, and Suchathites. These are the Kenites that came of Hemath, the father of the house of Rechab.