If you use bottom paint where it is peeling, just need to go with primer coat as was stated by Plym, then botom paint over it.
Save the white paint for "topside", unless you care to paint it white anyway.
The original powdercoat is an electrostatic process with a powder material applied with a gun, then gets baked on to form it.
Eventually, if you own the boat long enough, all the powdercoat will flake off, as with any other coating system. I have about 40% of the original remaining.