I rented a kayak from Sea Trek kayaks in Sausalito, and paddled out through the Golden Gate Bridge into SF Bay.
The outfitter http://seatrekkayak.com/ is a really nice company. They have good equipment, and are very friendly and knowledgeable about the area.
They gave me a Valley Avocet boat, because the Valley rep now works for them. They are just getting into British boats with skegs, and away from rudders.
This is a really nice paddle. The Bay has strong tidal flows, and I had to use eddies, and paddle against the current to get out. The whole North side of the bay seems to be open space, or parkland. There were huge rocky cliffs, and little pocket beaches.
I had a nice lunch, and one park, and picked-up some interesting trash at another one.
I got all the way to Bonita Pt., which is where the bay gives way to the open ocean. The weather can be very intense there, but there was only a few feet of swell, and very little wind, so it was pretty mellow.
If you drive or walk a trip it is much easier to remember the directions.