Happy Fish Swim School
When my son was three, I did a lot of research to find a swim program I thought would work for my too-frequently-wary-of-trying-new-things son. Thinking back to my own childhood, I made a mental list of all the things I hated about swim lessons: cold pools, not always so friendly instructors, one or two weeks sessions where I was expected to complete certain goals. I enrolled my son at a school where the water is 92 degrees farenheit, the classes were year round so that he learned at his own pace and comfort level, and the instructors were not under pressure to have the kids learn within a certain time frame, hence less pressure on the child. I enrolled my son in a class but there were never more than 5 or six in the class, and I think at a young age having other kids around might make it more interesting and fun for the child. Happy Fish Swim School is way down in Fremont (they have another school in Livermore), which is probably too far for you to want to drive, but I would keep in mind the things to look for in a swim school. Blowing bubbles was a big deal back then, now my 10-year-old son still swims at Happy Fish but just for fun and exercise. Good Luck!