Cut up some plastic cups, put a sliced balloon in the top and add something to shoot (marshmallows, pompoms, paper balls, Legos, etc) This is great for a child's pincer grip as well as hand-eye coordination. Put a bucket on one end of the bathtub during bathtime and make this is great game for them.
Practice the "ironing board" in the pool. Having kids relax as they float in the pool helps them gain confidence in themselves and in their capacities in the water. This is also a great way to stretch them out and sway them to have the water stimulate their skin. This can be very calming.