Found it.

I wrote a post two years ago about my encounter that, itself, was several years further in the past. In that post, I mentioned that there were TWO such couples here in the Toronto area that were father/not-daughter couples. Unfortunately, due to the distance in the past that they were, I had blurred both encounters together. While I do remember the girl clearly, I have forgotten the boats' names and anything else about the couple except the girls' faces.

Such are the memories of the aged.