[Serious] Nuclear war survival guide.

[Paleophyte]

They use enhanced fallout as its primary means of inflicting damage inland, not as byproduct of ground burst against targets on the coast,.   One example is russian deployment of nuclear powered unmanned miniature submarine that carried a massive 50-100MT warhead.  the submarine’s size abs low speed means it is all but impossible to detect.    it is meant to sail near enemy coast and detonate underwater, throwing up enormous cloud of radioactive water that will disperse down wind leaving a 1000 mile long lethal fallout tail.   if such a weapon is denoted off new york, the area of leath al fallout will reach miami.

I'm not sure who is projecting this but it's very wrong. For a start, Miami is upwind of New York, so you'd want to park that sub off Miami, not the other way around. Though you'd be better off hitting the west coast or the gulf given the wind directions. Not that it'd make much difference, because nuking water is woefully inefficient. The majority of the neutrons get soaked up as stable isotopes. You'll get a little tritium and radioactive oxygen but not much. Unless deliberately designed to beach itself, seafloor sediment would only be caught up in the periphery of the blast and wouldn't get much neutron flux. Much more effective to use an old fashioned cobalt-salted bomb. And those massive warheads are massively wasteful. The overwhelming majority of their energy punches upward through the relatively thin atmosphere and is lost to space. In doing so it's going to throw astonishing amounts of radioactive crud high into the stratosphere where it will circle the globe and rain back down on the very people who launched it.

All of that neglects the fact that these weapons would be useless to negative utility in a nuclear war. Sure, you can cause massive civilian casualties days after the first strike. That has little to no effect on the enemy's military, especially their nuclear weapons. The very weapons that might have stayed in their silos in a more limited exchange but which are much more likely to fly after these more indiscriminate dirty weapons are deployed against civilians.