We took DD1 swimming from 8 weeks and she has had pre school lessons from 3.5. She was a competent swimmer by 5.
DD2 has been going to Waterbabies from about 8 months. She’s now 1 and is extremely water confident, can swim underwater happily, kick up to the surface, grab on and climb out, but she can’t swim on the surface yet.
The main thing is they both adore their lessons and they really enjoy swimming.
I’m a good swimmer, but I would struggle to teach them. It’s not the same as being able to swim yourself, you need to know how to break it down into different skills.