"For Christ also died for sins once for all, the just for the unjust, in order that He might bring us to God, having been put to death in the flesh, but made alive in the spirit; ¹⁹ in which also He went and made proclamation to the spirits now in prison, ²⁰ who once were disobedient, when the patience of God kept waiting in the days of Noah, during the construction of the ark, in which a few, that is, eight persons, were brought safely through the water. ²¹ And corresponding to that, baptism now saves younot the removal of dirt from the flesh, but an appeal to God for a good conscience through the resurrection of Jesus Christ, ²² who is at the right hand of God, having gone into heaven, after angels and authorities and powers had been subjected to Him," (1 Pet. 3:18-22, NASB).

     The above translation in verse 21 from the NASB is a good translation: "and corresponding to that, baptism now saves you."  The key word in this section is the Greek antitupon. It means "copy," "type," "corresponding to," "a thing resembling another," "its counterpart," etc.  It is what the NIV translates as "symbolizes," the NASB as "corresponding to that," and the KJV as "like figure."  Baptism, then, is a representation, a copy, a type of something else. The question is "Of what is it a type?", or "baptism corresponds to what?".  
     If we look at the context, an interesting possibility arises.  What does baptism correspond to? Is it the flood? Or, is it the ark? What was it that saved Noah and his family, the flood or the ark? Obviously, it was the Ark. Noah built and entered the ark by faith and he was saved (Heb. 11:7). The flood waters destroyed the ungodly.  Also, Peter consistently refers to the flood waters as the means of destruction of the ungodly (2 Pet. 2:5; 3:6), not the salvation of Noah and his family.  Rather, it was the Ark that saved, the ark that Noah entered by faith.  It may very well be that baptism refers to the Ark, not the waters which may be why the rest of the verse says, "not the removal of dirt from the body but the pledge of a good conscience toward God" which is consistent with what Paul said in Col. 2:11-12 where He equates baptism with being circumcised of heart.  In other words, Peter clarifies that it isn't the water baptism that saves, but the appeal to the heart.
     Some see this interpretation as problematic since it seems that "water for water" would be a better typology:  the water of baptism with the water of the flood.  Furthermore, if we were to look at the flood waters as the thing that removed evil from the land, we could say that "correspondingly," the waters of baptism removes the sin from our hearts.  Though this reading seems a bit more natural, it too has problems.  
     The water of baptism is not what saves us, the sacrifice of Christ does which we receive by faith.  We read numerous verses about justification by faith (Rom. 5:1), salvation by faith (Eph. 2:8), etc., not justification "by faith and baptism," or salvation "by faith and baptism."¹ The fact is that salvation is received by faith.  Peter, not wanting to declare that baptism itself is what saves us, quickly adds, "not the removal of dirt from the flesh, but an appeal to God for a good conscience."  Water baptism, then, must accompany the work of the Holy Spirit in the person.  Peter's explanatory comment shows us that the act of physical baptism is not what saves, but the "baptism of appeal to God."  This appeal to God is by faith the same as Noah's faith in God led him to build the Ark, enter it, and remain in it.  It was the Ark that saved Noah, not the flood waters. 
     The flood was for Noah a type of baptism even as the passage through the Red Sea was a type of baptism for the Israelites.