I don't know what's going on w Crab these days in the Bat Area :
http://www.sanfrancisco.com/crab-season/
then there is this :
http://www.sfgate.com/news/article/Don-t-eat-Dungeness-crab-California-health-6608939.php
and this
http://www.sfchronicle.com/science/article/Hopes-for-crab-season-run-low-slight-prospect-6736479.php
Id at least ask about it while there.
of course, you have to like crab.
PS :
I always try to go here :
its old, you have to wait, but its got what it takes every time.
sand dabs. etc