I was in Martinez in my Catalina 27 a couple years ago, and at that time it was OK, albeit you had to be a little careful (I have 4ft 6 in draft). If they now have dredged to alleviate draft problems, Martinez is a great little town--lots of antique shops on the main street, an Amtrak station right at the harbor to swap crew (simiilar to Antioch), and friendly folks. Not as well kept up as Benicia or Vallejo, however.
Peter