No one gonna add races if you don't give the coordinates.
I believe that all of the races should be located in the Los Santos beach. SF beach has a lot of Fishermen who would like to cruse in peace with out any trouble or someone bothering them
well I use that route wich you colored Red in the map ...well in the middle before you enter that big spcace there is mud / high ground you can't pass whatever you do i'm pretty sure about it as I host my Trial tests ther and I also use it with my Squalo .