Many pools offer "swim lessons" for babies once they are 6 months old. I put this in quotes as children generally are not developmentally ready for formal swim lessons until at least age 3 or 4. Most programs for a 6-month-old are a parent-child class where the parent holds the baby while in the pool. This is the perfect set-up for an infant stimulation activity!
Together you will enjoy the sensation of the water. Water is caressing and its buoyancy will be a whole new feeling for you both. Also, what a great change of pace during the winter months!
A good class will have you singing songs, moving through the water while holding your baby, eventually experiencing splashing water, and possibly even having baby go under water. You and your baby should be enjoying yourselves; this activity not only should build a foundation for a love of the water, but should provide a quality face-to-face bonding experience between you and your baby.