Santa Cruz?

Pt reyes or Sea Ranch further North.

so who would just "drop in" uninvited?

The beautiful seaside town of Elk. It's above Gualala.

Just don't post it on FB.

Santa Cruz , Monterey, Carmel

Charter a ship and get married at sea.

Hornblower yachts does weddings on the bay.

How about Sacramento? http://sacramento.about.com/od/localgovcivics/a/marriagelicense.htm

Not Sacramento...so many other places that are much more memorable.

Yes, but they could take the train to Sacramento.

Nevada City is a charming historic town in Gold Country and is only about 2 hrs away.

Pacific Grove area

Inexpensive
We just came back from staying at a nice VBRO Condo across the street overlooking grassy picturesque Berwick Park on Montery Bay.

Lots of free parking on the street, very popular wedding location. Lots of fun things to do in the area.

Expensive

The Lodge at Pebble Beach (or at just have Brunch. They validate the 18 mile drive fee...)

http://www.pebblebeach.com/accommodations/the-lodge-at-pebble-beach

http://www.ci.pg.ca.us/recreation/p-berwick.htm

http://www.vrbo.com/115295

Oh, wow, thanks for the links. And the replies in general. The ship idea might be good, though I hope no one would get sea sick :/
Oh, and mztery, exes...

Getting married with Jerry Brown as officiant on the Capitol steps or in the rotunda would be memorable even if you didn't ride the train.
How about Alcatraz? Also memorable.

If I were an ex and wanted to mess up my ex's wedding , 2 hours would NOT stop me.

DebitNM:

mztery:

Is Tahoe too far?

Many small vineyards along Hwy 49 or Hwy 50 have weddings. Along Hwy 50 near Cameron Park is Cielo Winery/Estate (www.cieloestate.com/). It has an old Victorian house with a bandstand and a nice banquet facility. Pretty views of the vineyards also.

I was at several vineyards in the Shenandoah Valley (off Hwy 49 near Plymouth) that have areas for weddings and the views of the vineyards/rolling hills are spectacular.

It's rare that one gets sick on a charter that might go out the gate a little ways and just cruise around. Or they might even just cruise around the bay.

Just to be safe however - there are "patches" - small - round band aid type with medicine - you can put on behind your ear before you embark, and I have to find the name but there is even now another "sea-sickness" medicine you can take while underway if you get a little green in the gills.

There are also nice vineyards and venues in the Sacramento Delta to have weddings. A few to check:

http://www.scribnerbend.com/

http://wilsonvineyards.com/weddings.php

http://www.oldsugarmill.com/index.html

http://www.grandislandmansion.com/

http://www.rydehotel.com/index.html

If you are worried about an ex showing up uninvited and causing trouble go with the cruise and hire an off duty police officer.

There is a docked boat in Sacramento that is now a hotel on the river Delta King, restaurant, bar, they have packages

http://www.deltaking.com/

I second NancyTwo's suggestion of the Hornblower Yacht. It's a wonderful experience. The boat is huge and heavy so I think your guests are not likely to get seasick as you sail around SF Bay and under the bridges. Tomsd is correct is saying that folks worried about seasickness can use the scopalamine patch. It works wonders, but I believe you need a prescription. There is also over-the-counter medication available (meclizine has worked for me).

The Hornblower Yacht is a large vessel so it might be too pricey or perhaps too large for a smaller wedding party, but there are other smaller and more affordable yacht charters that sail SF Bay (in some ways nicer, because they are more intimate). A friend of mine rented a small yacht to sail on SF Bay for her 25th anniversary party. It was fabulous.

Rather than seasickness, I think your biggest worry would be the cold and fog!

Haha, the two hours is just so the guests don't have to go too far, we'll definitely have security. I don't want to have to knock anyone out on my wedding day
But the cruise does sound nice, it'd stop late stragglers from walking in halfway through as well, though I really want to get married under a tree so maybe a vineyard is the best way to go..

Hakone Gardens in Saratoga is beautiful:

http://www.hakone.com/plan-your-event/weddings-receptions.html

ttt

FWIW, my son recently got married "under a tree". It was a beautiful place, but not in California. Just wanted to say I think your "under a tree" idea is a good one!