There are many benefits of introducing your child to swimming whilst they're still a baby, including improved physical development as well as social development not to mention fun! However, the benefit that is overlooked most often is that of cognition or mental benefits which are incredibly important for the development of children as a whole.
Have a go at making your own Magic Rainbow Milk. Kids of all ages will love it! Magic Rainbow Milk is cheap, quick and easy to set up and if you do it outside (highly recommended!), theres not too much mess to clean up afterwards.