Depending on what you're aiming to achieve, then I'm all for floaties, under strict supervision.

We've just returned from a holiday where there was a pool - my boys swam every day. DS1 (almost 3) has done swimming classes for about 18 months. We put him in floaties so he could have a bit of fun in the pool. He adored it. Swam/floated around happy as larry. We took the floaties off for a bit each time so he could remember that at his swimming lessons he doesn't wear them. And he had his first return swimming lesson on Saturday without any problem - he didn't try to swim/float etc as if he was wearing them.

We put floaties on our 13 month old too, so that he could enjoy the pool. I or DH still held onto him, but the floaties sure helped him to stay afloat and have a bit of a splash. He's not in swimming lessons just yet, but he will be within a couple of months.

I personally think that if you're only going to swim every now and again in the hot weather, then the floaties are beneficial. They certainly gave us a little more piece of mind for the leisure swims that we had. It helped the kids stay afloat in the water and enjoy it more too. And as I said - our DS1 had no trouble making the distinction between floaties on/ floaties off.

I think if you're worried about your 14mo getting too confident then make sure you give him some floatie-free time, and take him to swimming classes.