Many years ago, Alviso was a thriving town and had its own marina and all. But over time that all disappeared. Santa Clara County has recently rebuilt the ramp and is having the official ribbon cutting/opening this Saturday. This is a new location where we can launch from, so could be interesting to check out. Supposedly, there will be free food and live entertainment. And I think there will also be kayaks available for (limited) free use.
Some details on the event at http://www.regathon.com/alviso/ (plus also details if you want to help out by volunteering).