I find I evaluate safety in really different ways than most people do. This came up a few days ago at the cottage with my inlaws when Elli and her friend wanted to take their new little kid kayak out for a spin. Their new toy is a plastic board, basically, that floats because it is full of air. It barely stays above water with the two of them in it, but they have an absolute blast paddling it around together.
The conflict arose because my inlaws wanted the kids to stay within a few metres of the dock and I wasn't having anything to do with that. They both had lifejackets on and I was in the adult kayak alongside them so it would be extraordinarily unlikely for anything bad to happen, but my inlaws were still very worried and keen to keep the kids on a leash. Instead I led them merrily out into the middle of the lake where they propmtly capsized.
Now you might think that this was me losing the prediction war, but in fact it was exactly the result I wanted. A clear day, good supervision, no real chance of problems - that is precisely the time when you should learn what capsizing is like and how to cope with it. I was hoping they would tip, in fact, so that they could learn how to get themselves back on board. They managed it just fine and off we went around the lake, playing chase games and races and looking at wildlife. They capsized yet again, and again I got them back onto their kayak.
In the end they told everyone that the best part of their adventure was the capsizing part!
I think it comes down to time horizons. I think that long term letting kids get out there and try things and test themselves is a positive contributor to safety. When they can try things without real risk they should, so that when they are older they will have those experiences to draw on. Safety isn't about avoiding all behaviour that has potential negative consequences, it is about knowing what the real risks are and making sure you mitigate them as much as possible. Tipping within sight of home while an adult is around to bail you out isn't a real risk. Never trying anything so you end up not knowing what the hell you are doing on the water is a much greater risk in the long term, and long term is what I care about.
Plus zipping about on the lake and watching my little one make the transition from being terrified of tipping and nervous about the kayak to laughing about tipping and comfortable with the kayak is a wonderful thing. There is really something to be said for watching your kid make big strides like that, particularly when it happens over the course of only an hour and a half.