Prefigurations of Baptism in the Old Covenant
The Church has seen in Noah's ark a prefiguring of salvation by Baptism, for by it "a few, that is, eight persons, were saved through water":
The waters of the great flood
you made a sign of the waters of Baptism,
that make an end of sin and a new beginning of goodness.
Source: Catechism of the Catholic Church (Vatican.va)