sox...
First, you must remember that God created the entire universe and all that is in it in 6 days. The wonder of that event is wondering why it took Him 6 days, when clearly He could have accomplished the feat instantaneously, and I still ponder on that one from time to time. It is equally clear that He is capable of creating a chain of Islands like the Hawaiian Islands in an instant - that also would not be a problem at all for Him.
A concept that you have not considered is the possibility that during or shortly after the Flood of Noah's time, the movement of plate tectonics and the mechanisms of hot spot eruptions were both very much faster than now enabling the islands that we now know to have been created much more quickly than science now supposes. I personally tend to like that concept for it fits in nicely with other concepts I have concerning the original supercontinent of Pangea and how it broke up into the continents as we know them today. However, I must concede that the first proposal is very easily the correct answer, and that there are other possibilities.
mlsoft