I recommend this 100%. It gives the baby freedom to move, and provides comfort, support to their little backs and neck at the same time.
My baby is 3 months and she’s used to room temperature/fresh water. I started with the feet to make her feel confident and comfortable. I let her guide me to when she was ready to get the legs and up to the tummy in the pool. Then up to her chest with me.
After that I put on the jacket, first I was holding her and then little by little she made me understand she needed some freedom. Although I was always right next to her. She started to notice she could move when she moved her arms and legs and loved it.
I got the cap to make sure to cover her little ears to avoid water getting into them to prevent infections, so be mindful and careful with that when you put the babies in the water 🙈.