glowing ball just under the surf about 2 1/2 feet off the beach south of san francisco/ocean beach approx 9/94

a friend and i were walking her dogs along the bluff overlooking the water just south of ocean beach.  it was getting dark and we noticed a glowing object about the size of a basketball in the surf.  we assumed it was garbage and phosphersence but it was a perefct orb shape.  it then seemed to stop breifly before it began to pace us about 2/12 feet off the beach moving south.  we watched it for several minutes trying to figure out what it was.  when we determined it was now moving south she then became so scared she ran to the car.  I caught up to her as she was heading back to the small parking area. before we got there we saw a white jeep cherokee that we assumed was a park service vehicle there about the thing we saw. as we got closer we found the driver door opened and the vehcle running with it's headlights on. there was another couple by thier car and we asked about the jeep and they said someone must've fallen off the bluff or something.  there was nothing in the paper about any accidents and there was never anything reported about that evening.  we have never forgotten that incident and we've never seen anything similiar before or since.
Witness indicates that the date of the incident is approximate.  PD