Fish-Hawk.Net

I was recently reading that in some areas of Quebec you can fish with a SPORTS Ontario license but I'm trying to fully understand this. My girlfriend lives in Chateaguay (which falls under zone however the website says:

"In a portion of lac Saint Francois located west of a line drawn from beaudette point on the north shore to Saint Louis point on the south shore"

I have no idea what this means, I read the maps and I can't find any line it's talking about.

This thing is so confusing and never worded properly or made easy.

I live on st Francis, the way the rules work is I can fish on the Quebec side with my Ontario licence however I have to follow their rules. For example walleye on the Ontario side has no slot size however on the Quebec side it does so if I am fishing on the Quebec side any fish I catch or have in the boat needs to fall within that slot size even if I caught it on the Ontario side before crossing the border