What is the next step for Infant Swimming Resource (ISR) kids?

As a mother and an ISR instructor, I'm constantly asked, "What is the next step after ISR?"  As any ISR parent knows, the obvious first answer is to go home practice and master the ISR skill set.  ISR gives our children a great toolbag of water skills to work with and enjoy the water for years.  But once they have mastered these skills, are old enough to take verbal instruction and are truly ready for the next step, then what. 

I've put this program for parents and instructors to address how to take such a skilled young student and advance them to the next step without corrupting all the great aquatic skills they came with.