Swimming is a fantastic sensory experience to do with your babies. It obviously also teaches them a life skill. There are lots of interesting things that go with swimming. For example, for first six months of their lives, your babies will have what's called a dive reflex, which means if a baby is placed into the water on its front, the gullet will close off to prevent water from being injected into the lungs and the stomach.
Babies up to about the age of six months, if they're placed in the water on their front, they will look like they are trying to swim. There have also been some studies to show that babies who are taken swimming from an early age and are taken regularly will show better balance as toddlers and young children.