Walk past almost any Florida backyard pool on a Saturday and you'll see a kid in arm floaties or a puddle jumper vest, and a parent nearby who assumes that's roughly equivalent to a real life jacket. It isn't, and the gap matters most in exactly the situation where it would count.
They add buoyancy to the arms, which can help a child stay upright while paddling, but they don't reliably keep an unconscious or panicking child face-up. If a child tips forward, arm floaties don't correct that the way a proper life jacket is designed to.
A properly fitted life jacket is built specifically to keep a person's head above water and face up, even unconscious, through buoyancy placement around the torso rather than the limbs. That design difference is the whole point. It's built for the worst-case scenario, not just casual floating.
For a non-swimmer around open water, a boat, or an unfamiliar pool, a real life jacket is the right call. Arm floaties are fine for supervised, casual play in a pool where an adult is within arm's reach the entire time. Not a substitute for either supervision or a proper vest.
The safest option is a child who can actually swim.
See Kids Program