Bill,
I think Hot Tubs are grouped with Pools for simplicity(?). The similarities in potential hazards (usually located outdoors, barefeet on grass or concrete) probably wouldn't justify a whole different set of rules for Hot Tubs than for Pools. (I can imagine someone getting out from the Hot Tub or Pool to chance a burned out lamp, or plug in a radio while still wet and standing on grass or a patio).
Both are separate from bath tubs.
