Dd2 is nearly 5 and she's in beginners swimming lessons. She can't yet swim without aids. She had a week of intensive lessons in August and on the back of how good those were, we rebooked for a whole term, once per week. The intensive course had teachers who were in the water and very hands on. The teacher she now has - which is supposedly for the same stage lessons - doesn't get in the water.
Some things - like hold one float and use one arm - DD2 just can't do. Instead of being helped, she's just allowed to walk across the pool!