who before were disobedient, when God waited patiently in the days of Noah, while the ark was being built. In it, few, that is, eight souls, were saved through water.

 Peter has been speaking about the wicked men who were disobedient and corrupt in the days of Noah; they were ultimately destroyed. But in the destruction by the flood eight people--Noah and his wife, his sons Shem, Ham and Japheth, and their wives--were brought to safety in the ark. Immediately the idea of being brought to safety through the water turns Peter's thoughts to Christian baptism, which is also a bringing to safety through the water. What Peter literally says is that baptism is an antitype of Noah and his people in the ark. 