This is just going to be me babbling.
As a former longtime resident of Miami and a fan of Art Deco and MiMo, I've been mulling over the concept of Miami related articles. One notion I've had is of a small, technocratic group (completely unaffiliated with any other pre or post-war groups) dedicated to continuing human existence in underwater habitation. It makes sense to me, there's always been a lot of money in Miami, and a lot of private universities. Between the study of marine biology and engineering intended to stave off hurricanes, along with some of that Fallout magic, I think such a group could work.
Just to be clear, these aren't guys in power armor tromping around the beach, they're the descendants of scientists, engineers, and their financial backers who are out for their own survival. I think I'll give them a hankering for antiques. Unlike the BoS who are strictly out for technology, these guys would value cultural and artistic artifacts more, that keeps them from being completely isolated: they trade fish and processed kelp for fine china and whatnot. Aesthetically, I'm envisioning the design sensibilities of Bond villains from the 60s.
I also like the idea of the city being partially submerged, with bridges raised between the upper stories of buildings kind of like they did in the Pitt. There's some room for Water World style antics too, though I'll stay away from Costner's amphibious mutants.
EDIT: For those of you who aren't familiar with the visual design I'm implying, try looking up images from the game Evil Genius. If any of you are fans of the Venture Bros. or Johnny Quest you might also get an idea.
EDIT 2: So I'm calling the underwater technocrats Aquaculture unless I think of something cooler. Their leadership is called the Nu Council because it implies a "new way," of life and because it's the masculine form of the name Naunet, the mythological Egyptian water goddess. I imagine them piping ambient music in their underwater city, different stuff than you would hear elsewhere in the Fallout world:
While I happen to like the music and images I associate with Aquaculture, I imagine most people in the Fallout world would want to punch these guys in the teeth really hard.