Passing a formal drownproofing class used to be a requirement for graduation at Georgia Tech.
http://en.wikipedia.org/wiki/Drownproofing
They dropped it in the mid 80s, several years after I graduated.
There were people who just didn’t float very well using the technique.
This is similar to what I was taught in the Navy.
I dont recall if they bound our hands, but the did bind our feet..