We're not liveaboards but we spend every moment we possibly can on board with our kids, now 13 and 15. In fact we're on the boat this weekend right now, even though it's 48 degrees outside and we're one of the last boats still in. I have noticed a lot of the tendencies in them that you hear about "boat kids" - hopefully more polite, more likely to engage adults, more independent and resourceful and skilled in fixing things. As they get older I have noticed it's "boat specific" though. Maybe it's my imagination, but I often get the feeling that those habits only or mostly kick in at the marina or on the water, with and to other boaters in other words, but it doesn't translate back in regular life on land.
The boys wouldn't think twice about talking to random adults on the docks or joining groups of unknown kids, or helping strangers tie up thier boats, but they generally don't assume that familiarity and ease at home, back on land. One afternoon Nicholas disappeared for a while - he came back with a wad of cash because he helped one person at the launching ramp who tipped him (unsolicited of course) and then he just stayed there helping boat after boat and many of them handed him tips. That kind of thing would never happen on land.
They also have some close "boat friends" - that they only see half the year when it's not snowing - but oddly, they don't seem to have any close land friends. Kind of strange. And they love it down here, even when its cold or rainy or quiet, when at home they're bored and fussy in ten seconds. Life on the water is a fascinating thing for kids and so interesting to watch.