Swimming is the best, I have always been in the water, last week when the weather broke we hit the rope swing after mountain biking.
Griffin (soon to be seven at the end of June) has been learning slowly but does pretty well. We never took him to lessons as we are always in a pond or river instead of a pool. I think the first thing I taught him was about undercrrents and not panicking. When he was five we floated together on our backs through some pretty rough water. (not deadly but strong enough currents to teach a child what to do in a bind). He learned about undertoes at a large waterfall, and is now loving the water. Might not have been the safest way to teach a child to swim, but Griffin has always had a way of rollig with the punches in his life.
Don't know if that helps, but let us know how they do.
Thanks
Rusty