One might think Peter was referring to Noah's flood! They would be incorrect! The "tell" on this is "and the earth standing out of water and in the water,"....According to the writers account of Noah's flood, the water was some 24.5 feet ABOVE the highest mountain, right?....If this is true?...There would be NO earth standing out of the water. Right? Apparently, then, Peter wasn't teaching concerning Noah's flood.
What Peter was teaching, or trying to impart, or "feed" the sheep, was " heavens were of old", and, "the world that then existed perished, being flooded with water." Peter is teaching about the previous earth and heaven age! Compare, " But the heavens and the earth which are now preserved by the same word," Peter is teaching about this current earth and heaven age. What is even of much more importance, is just who, or, whom Peter was teaching about! One could say, Peter was teaching about ungodly men, but it goes even deeper then this, and the whom Peter was teaching about! Which is "The OVERTRHOW" or, "Katabol"! Those that make men ungodly, and MAKE men "Willfully Forget". God caused Noah's flood, as a REMINDER to those of the overthrow! What's more?...God didn't relent from the flood waters, until, those of the overthrow, sued for a truce, via the dove with an olive branch! Remember? The raven he sent out first, never came back! There's even a demonination that call themselves "Noahhides, er Noahhites" er something like that.
(Jesus' disclaimer) If, perchance, I offended thee by "overloading your donkey", so to speak, with the truth? Then you have my permission to slap me on the face! After which I shall turn my face, so you may slap the other side! THIS, was what Jesus was teaching about in those verses, and NOT being a pacifist!