[sokoloff]

The ones which are just placed on the arms and not tethered to each other have a failure mode where they easily come off if the child puts their arms straight up. Unfortunately, this is also a common drowning fear response.

In general, I want people to have full market freedoms, but I put those water wings pretty near lawn darts in terms of danger.

[OkayPhysicist]

I'd call lawn darts safer, as the danger with them is a lot more obvious. Everyone understands that throwing sharp things at people will lead to injury. It takes a significantly more informed consumer to know that a product masquerading as a safety tool is ineffectual at best.