Welcome to our forum.
I have 2 stories.....Sitting in the tub, a lot like you, it was a calm warm night...all of a sudden a big ball of orange and blue light, then the crack of thunder! It was ball lightning that hit 2 houses down! I did not even bother putting the cover back on, just ran to the house. After the storm, went out to a tub that was overfull of water and many leaves and gunk..great fun to clean up!
"we have seen a few tubs from this area that have had direct hits"[/b]whoa.....I had never even really thought about getting hit by lightning in the hot tubbut most of my soaking is in the winter when there are less thunder stormsthat would be a real bummer, but I guess you'd never even know it if it happened!