Scooping items floating in water: this activity can be done with any item that floats, and can be changed around themes, holidays, or to increase difficulty. Children work on motor skills, but can also start incorporating color matching or sorting as time
Make a backyard bowling alley. Add food coloring to clear plastic bottles of water. Use party streamers as lane margins. Add glow sticks for night bowling. (These would make great outdoor table nightlights also with the glowsticks, gonna try it!