We use inflatables exclusively when we are out on the water cruising. I carry the traditional "orange uglies" but when we are on the boat, everyone has an inflatable on. Without reading the article, here's my experience with these things.
There are various models of these things and they do make them for kids. Here's a shot of my youngest a few years ago when he was 6 years old:
The child version of these vests (up to 50 pounds and 50 to 90 pounds) has floatation like a ski vest and then when the trigger is activated, it blows up behind the head as well as around the chest. I have the child version of these things set so that they inflate automatically when they are in the water.
The SOSpenders version of these things you wear around the neck can be activated automatically by the disolving of a bobbin in the trigger also or they can be configured to be manual activation only. I've set ours to be manual activation only for everyone (again... except the child versions). Let me explain why I've set them to manual.
Every year when I repack these things, we have a "abandon ship" drill and everyone gets to go in the water off the boat (at our dock) in their vest. If you've never experienced one of these things inflating, you should. It is very cold air and they are tight around your neck and chest and you'll definitly float but you won't be "swimming" or moving much. They are also so snug around the neck it would be very hard to put it back on inflated if it is taken off. We all determined we wanted to be able to have some mobility in the water to get in the life raft, round up kids, etc. and "pull the trigger" if needed. Guest life jackets, however, are automatic.
The other issue with the automatic bobbin is that any moisture or high humidity can and will set them off unexpectidly. If you have to be out in the rain or get any spray, you don't want the life jacket going "POOOOF".
The life jackets can be configured to manual by replacing the disolving bobbin cartridge with a manual cartridge:
and then a little tag hangs out to identify it:
I'm sure I'm violating some rule, but everyone is in a jacket of some sort when we are underway and, as I said, I also carry the orange uglies and also ski vests on the boat for water sports.
You do have to maintain these things and replace the CO2 cartridges, check the inflation mechanisms, and I also have strobe lights in each of the vests packings that have to be checked. You also will need to carry some repacking supplies on the boat in case you inflate them for any reason.
Now here's a shot of what happens when they inflate when you least expect it. We were on our way from Havre de Grace to Annapolis the other day and I had my hand on my trigger and hit a wake... POOOOF.. I didn't expect it and it blew up and my son thought I was having a heart attack and reached over and unbuckled the vest. I said some choice words. My wife snapped the picture laughing....