Here's a beach pic at the Presidio, north of San Francisco, not that far from the Golden Gate bridge (seen on the extreme left).
Weather's a bit dull, but there's plenty of sand on the beach. Here's a sunnier view.
The small hut on the right contains the tide gauge for San Francisco. Both pics are from the NOAA station information page for that gauge. Based on the first pic, how would you rate the chances of the gauge registering low water accurately?