Nice place to rent kayaks right in the city, where you can get a good view of the city skyline, the Bay Bridge, and the baseball stadium. The owners (husband and wife?) are really friendly, and the entire operation had a mom-and-pop feel to it.
Paddling around splashes water so you will get a tiny bit wet, so bring appropriate clothes (or maybe a change of clothes for after). I left my sandals on the dock and went barefoot. You can buy water and snacks at the checkin desk (and don't forget sunscreen), and rent a dry-bag for your belongings. I recommend two hours, since getting ready, onto the kayak, and leaving the dock area all eat some time which would make a single hour quite rushed. We were able to paddle to the bay bridge, back to the dock, to the baseball stadium to watch some of the game, and back all in two hours. If you're prone to seasickness, take some dromamine or ginger candies before you go!
Go on a nice sunny day when a baseball game is being played.