the text you used in 1pet 3:21
says :
18 For Christ also suffered once for sins, the just for the unjust, that He might bring us to God, being put to death in the flesh but made alive by the Spirit, 19 by whom also He went and preached to the spirits in prison, 20 who formerly were disobedient, when once the Divine longsuffering waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight souls, were saved through water.
1pet 3:20 has nothing to do with baptism.