Basically, I figured that a major setting for post-apocalyptic stories that hasn't been jumped on yet is submarines. Logistically, one of the best places to survive such an event would probably be underwater, and the setting could be used for a lot of high tension battle sequences. Submarines are usually stocked to last up to and over 3 months, and the cores of nuclear submarines can last DECADES without replacements if well maintained. A "pirate submarine" could slink around hunting other submarines, ships, and oil rigs, or docking on land at night for scavenger parties to loot the remains of the old world on land.
I figured the plot would follow the crew/ crew's descendants of a nuclear submarine from a eastern european country (the era and location of which would remain ambiguous to allow a mish mash of technologies and decade styles, anywhere from the 1920s to the 90s). The ship's captain would be a battle hardened older lady, one of the last remnants of the original crew, who's clearly been through a lot of shit, giving her an edge on many of the unexperienced captains who now patrol the irradiated seas. The adventures could follow a tone of different scenarios that the crew have to experience, all testing their morality and willingness to survive. Simple things from delivering goods from one settlement to another (settlements being stuff like sealabs, oil rigs and large self sustaining bunkers), fighting hostile vessels, to choosing to pirate others in times of desperation. The crew could be forced out of their seas, or choose to explore the world to see what else is out there. (edit: think the moral quandaries and exploration of star trek, but a little more grounded in earth culture, and more life or death survival.)
The societies seen in this world could be an interesting mix of modern cultures, and post-apocalyptical ones. Because the story wouldn't be bound to any particular time, a whole plethora of cultures/ styles of ship building that have since been homogenized could be seen patrolling the waters. Chinese junk ships, WWII battleships, turn of the century steam boats, ballistic missile submarines, fortified superyachts and cruiseships, 70s sea lab concepts, 1900s diving suits and stuff that only Jules Verne could dream of would all present similar threats in a dream like fashion, most under the guise of "they were taken out of mothballs after the apocalypse by people looking to escape the irritated mainlands. I want to not only focus on cultures and how this crew explores them, but also how those cultures meld with this new world to create something familiar, but new and beautiful.
As for some of the settlements, I think underground locations such as the Super-Kamiokande Neutrino Detector facility in japan and the US millitary Cheyenne Mountain Complex (both pictured below) would be great uses of real world locations that could be re-purposed into now post apocalyptic towns or cities. As well as that, Antarctic and underwater installations would likely not be touched by a nuclear war, so they too could be stopping places for the crew of the submarine. These settings would be a great way to show off how the military and scientific worlds would have different views on dealing with such scenarios, and I think the difference between the two could make for some good contention/ plot points.
Finally, I could also introduce the idea that a lot of parts of the world have sunk/ been flooded, meaning that the submarine exploration parties/ battles could take place farther inland, and possibly even in between skyscrapers and other structures. By playing fast and loose with when/ where the pre-war world is, I could do a lot of shit that a more grounded story might be limited by. The choice of having a old lady as the captain may or may not have been inspired by the "ladies rock" mentality that Mad Max: Fury Road has with the Vuvalini tribe. Also, having a sort of "laissez-faire" attitude to how radiation works, I think it would be really cool to introduce sea creatures that mirror the massive sea beasts that sailors used to spread myths about in the early days of exploration.
Below are also some photo references for the "vibe" I'm trying to capture with the story. Spent like over 2 hours collecting this pics so i hope u like :)
