We sail, power boats are a whole different thing. As kids we used to purposefully capsize our sailing dinghy's & hide in the air gap underneath them, because it was fun
& we don't dock, we anchor up in a bay for 2-3 days at a time & then move to a different bay, if we are on the move, then everyone wears a life jacket, tethered to the boat, if dd isn't in her seat then she has a life jacket on, which is also tethered to the boat. I also used to work with the coast guard here in New Zealand, as did my parents, we are very safety conscious & spend thousands each year on safety gear that we hope we'll never have to use.
I'm curious to know how much sailing you have done? I have logged 28 years, thousands of local, coastal & offshore hours & sail in some of the roughest water in the world, I know how to keep myself & my kids safe. Anyone who is in a collision on a boat, isn't a very good boatie, they should have been keeping a better watch & avoided the collision in the first place. In my years of sailing we have never even come close to having a collision. Also I wouldn't be thrown from the boat as I would be tethered on, the general consensus is, you stay on the boat, if you fall off you are dead, anyway who has ever attempted to pick up something that has fallen overboard knows how hard it is to retrieve things once they have fallen off the boat, that includes people. This is something we practice regularly. You just dont fall overboard. I have known people who have died while sailing & all them because they got separated from their boats & couldn't be found.
Where in the world did you put a 6 month old on a canoe? lol Where we sail there are lots of kayakers, who do the same thing, I obviously wouldn't put dd in her car seat in a canoe, as there is no room, & they are far more likely to capsize than the boats we sail on. Every time she or anyone else is in the dinghy they have life jackets on, that's not negotiable. We wear our life jackets if we are moving the boat, there's not much point in having them within reach, we also go for bright neon yellow or orange, with whistles. We take a grab bag in the dinghy, with flares, first aid kit, vhf, cell phones & food in it (it floats independently) just in case something happens between the big boat & the shore (because despite how it may seem) we are paranoid about safety.
& we're not the only ones who use car seats on boats.
http://www.car-seat.org/showpost.php?p=881303&postcount=15
this is the boat we sail on