These people had disobeyed [Noah's preaching, See II Pet. 2:5] back when God's patience waited [for them to repent, See Gen. 6:3], during the days of Noah, when the ship was being constructed. It was by that means [i.e., the ship floating them to safety through the Flood waters] that a few persons, eight of them, were saved [from destruction] through water.

This water prefigured immersion [into Christ], which now also saves you, not by removing dirt from the [physical] body, but [by serving] as an appeal [or, "pledge"] to God for a clear conscience through the raising of Jesus Christ from the dead.