water wings are also terrible at teaching kids to swim: they can't properly use their arms wearing wings.
I had both my kids (currently 3 and 5) learn to swim by having them wear inflatable vests. When they started they had fully inflated vests. every week or so I would deflate it bit by bit, until they are wearing a fully deflated vest. At that point the vest is just for emotional support, and they can pretty much handle the water without drowning (though still need proper lessons of course)
The funny thing is that I remember as a kid using a borrowed set of water wings (I'm assuming those are the inflatable things that go on the upper arms?). I was like 9 years old, and could barely swim by doing a back stroke (floating on my back, and somewhat making my way across the water). But when I put those water wings on, it gave me just enough support that I learned that afternoon how to do a breast stroke and side stroke, and ended up being a fairly strong swimmer after that (only used them that one time though).
That makes me think. Could one make a remote inflatable vest? Basically, one of those vests they equip aircraft with, but with a remote control attached as well. While deflated, it wouldn't have a significant effect on buoyancy or encumbrance, so the child could learn to swim naturally. If one notices one's child in distress one could inflate it with the push of a button.
And when it fails, and a toddler dies, the lawsuit would be enough to totally bankrupt the startup. Simply not worth the risk. I like the idea of using reactive technology to improve the cruft of aversion-type devices though.
I feel like this is why Hovding says it's "not intended for people under the age of 15". It's not that it wouldn't work most of the time, if not "all but a single time" and are simply protecting themselves from a possible lawsuit.
What's to prevent a condom-like "99% success rate" as legal backing for "haha can't sue us if it fails because we didn't promise 100% success rate"? Even though, effectively and when used properly, they have a 100% success rate... it's just there for legal reasons to prevent lawsuits.
When we put both my young kids through swim lessons, they were taught with "bubbles", little foam blocks that are strapped to the middle of the back, and the number of bubbles are reduced as their proficiency increases. That left their arms and chest free to work on actual swimming form. When working on kicks, they held on to little floating dumbell bars.
I had both my kids (currently 3 and 5) learn to swim by having them wear inflatable vests. When they started they had fully inflated vests. every week or so I would deflate it bit by bit, until they are wearing a fully deflated vest. At that point the vest is just for emotional support, and they can pretty much handle the water without drowning (though still need proper lessons of course)