Granted, I almost never fly and when I do, it's usually Southwest, but for those unfortunate people who might be thinking of flying on AirCanada be warned. They have cut out all their life vests in order to save weight and fuel. So if you have a small child or an infant, you'll have to figure out someway to hold on to them while also holding on to your hopefully floating seat cushion.
Apparently the law in Canada and I suspect here in the US, authorizes carriers to rely on seat cushions as long as your flight is not scheduled to fly more than 90 kilometers away from the shore (almost 56 miles). I don't think a champion swimmer could last that distance with a seat cushion.