C.Z.
6 months is not too young. I started my son at 6 months and he LOVES the water/pool! He is now almost a year. We go to South Bay Aquatics. He quickly learned how to hold his breath when going under the water which I think is a great skill for them to learn as soon as they can! At this point it's more about having them comfy in the water. You get in the pool w/ them and sing songs as well as float them on their backs, go under water, etc. I read an article recently that said kids that get in the pool earlier have less chance of drowning. Almost everyone in our class at South Bay started their kids around 6/7 months so it's very common. It's a fun event to do with your baby! They are only in the pool for 30 minutes and it wears them out for some good naps! There is always an instructor in the pool with you and they come around to everyone for some one on one time. The facility is only about a year old. It's very clean and the staff is very nice. You always get greeted when you walk in the door.
Occasionally we've had an older child (1.5 yrs older) be in our class and I've seen these kids when they first get in the water. They freak!!! I truly believe you have a window to get your baby in the pool where they won't be scared.
I've also talked to my pediatrician about it and she was not concerned at 6 months to have my baby in the pool.