DEMA is the biggie, but it’s not open to the public. It’s about 1/2 travel agents anymore...
There’s Our World Underwater in Chicago,is it?,,,and lots of other regional shows. Do some googling and you’ll find them easily, and look in the dive mgazines, also.
And some local dive clubs have blogs and websites, also.
Cheers,
Melissa, a retiree that still dives some.