First, identify the areas that may impact you by going to:
Southern California Marine Protected Areas
For La Jolla, generally the only area that I am personally concerned about is the Scripps Coastal. The nice thing here is that the western edge is the only thing I really care about. So, I entered a Waypoint in my GPS the north west corner. If I am east of that - no fishing. If I am west - hook up time!
In this context, I use 32° 53.000' N. lat. 117° 16.400' W. long. You could use the coordinates for the southern zone also, what matters (For me) is the Longitude.
32° 53.000' N. lat. 117° 15.166' W. long.;
32° 53.000' N. lat. 117° 16.400' W. long.;
32° 51.964' N. lat. 117° 16.400' W. long.; and
32° 51.964' N. lat. 117° 15.252' W. long.
If you are fishing another area, I would use the same methodology if possible. Some are crazy shapes and dont follow clean North/South - East/West lines. I do not know of any method of identifying a 'Zone' on Lawrence. If someone has a better idea, I am all ears.