What is meant by the ancient mantra of Church fathers that the Church is the Noah’s Ark of the New Covenant?

Noah is an OT typological prefigurement of Christ, and his Ark is of the Church. To be saved from the deluge, species had to follow Noah aboard his ark. Likewise, to be saved from the deluge of sin, people must follow Christ aboard his Church.

With regard to salvation, there is no separation between following Noah and being aboard his ark. Likewise, there is no separation between Christ and His body the Church.

Jesus, as the new Noah, came primarily to build a Church (Mt 16:18), not write a book.