Architecture could incorporate riads
The U.S. / world could have more public swimming pools / lessons
Hot tubs / pools in backyards could be open to all
Pools / hot tubs could be inflatable
Pools could be in shipping containers
Boats could have hot tubs and/or spas
Swim tethers / harnesses / cords could enable training in small pools
Swimming pools, basketball courts, private gyms/studios, etc. could be rented out
Swimming pools could be natural
Swimming pools could be see-through and between buildings
Pools could be made of saltwater
A swimming pool could be created in a river or bay
Ozone, UV light, and carbon could treat water instead of chlorine