What age to start swim lessons?

Those of you with older children, when did you start swimming lessons? We haven't done them in the past, but I would really like to get Mason in some this year - and I'm thinking Audrey too! I don't need them to be olymppic swimmers or anything, but it would be nice not to have to put a life vest on them the second we get to the pool :)

BethSummerville, South Carolina
    Where i live you can do a parent child swim class where u go in the water with child and just get them used to water. This goes until age 3 and u can start it as early as 6months. We did this class wen haiden was 2.5 and when logan was 2.5. I plan on doing it in the fall with vince.
    Then there is a toddler or preshool class. They go in water with help but you dont go with them. They have to hang hold on to edge. They have have to be 3-5years old. Haiden was 3 when he started this and logan was 3as well.
    Then there is level one-5. And they have to be 5 and older for this. And haiden has been in level one for a year now.
    About Beth
    Current: Summerville, South Carolina
    Birth: September 18
    On Moms.com since: Aug 18, 2013
    obsessed with babywearing, cloth diapering, and breastfeeding (but not judgmental about those that aren't). I'm a SAHM that works. Loves cupcakes, kittens, and glitter; hates spiders, housework and pessimism.