Geofag here with a little analysis of a potential location.
I compared one of Q's photos with the mud flats near Redwood City, using Google's maps in 3D (for what it's worth – difficult to get the angle I wanted). In this case, the San Carlos municipal airport is in view on the right side of the shoreline, and the plane would be flying south toward Moffet Field.
Mud flats are tricky. The mud flats (also used for salt production around the Bay at various times in history) can change appearances over time, even during the day due to tides. The colors will change, too, if there is salt production happening.
If this is truly a match, it would indicate that the Q plane photo was taken some time ago relative to the Google photo (due to construction, wetland rehabilitation, or whatever they're doing to the shoreline). I'll see if I can find a historical photo from the 1990s. I just wanted to share right now in case someone else is working on this. Personally, I'm still not sold that this is the exact location, but I did see some patterns.