Being able to float and do the elementary backstroke, when needed, is really important. You need to be comfortable with water occasionally drifting across your face as to breathe while on your back, too.
There is so little effort needed, once you can do these things.
> There is so little effort needed, once you can do these things.
Back in my water polo days I was a good swimmer but had so little body fat that if I exhaled I’d slowly sink. Had to have lungs full to stay afloat ;-)